( 1)

There are three canteens in our school, one canteen, two canteens and four canteens-I don't know why there are only three canteens missing, perhaps because 13 is a taboo number in Shanghai, and even 3 is counted. Then there shouldn't be four canteens, because one plus three equals four. In a word, this is an intriguing question that ordinary people like me can never understand. Call me ordinary because ten people stand in a row. You may not notice me when you see the seventh person, but my life has not lost its luster because I am just me.

The canteen is the most popular canteen in the school. On average, five dollars can make you not hungry, and six dollars can get meat. Moreover, you can also eat all kinds of strange things in the canteen, such as an orange petal in roast beef with potatoes, a coin in a green vegetable bag, or a lot of tea-making beads in tofu stewed with cabbage. Nothing will make you too sad, because after all, you didn't eat flies, but they didn't make you so excited. Even if you can eat a coin, it must be a dime, and because the steamed buns in the canteen are sold at a 10% discount, you still lose money.

My favorite dish is stewed tofu with cabbage, because it only costs three yuan. If you don't do much exercise, two yuan of rice is enough to eat. Because I often eat it, even if there is a pearl in the milk tea, it can't escape my eyes. What's more, those pearls have accounted for at least one-third of the stewed tofu with cabbage. I can assure you, I am like a worm in the stomach of stewed tofu with cabbage. I won't let you down as long as you ask. Of course, don't ask me how I know this, I can only tell you, which is why I am different from you.

(2)

The source of these pearls is simple. They were originally made of milk tea. In fact, when the canteen first started to buy milk tea, the business was quite good. You met three people in the canteen. If two of them are carrying rice plates, then the other one must be carrying a cup of milk tea. Milk tea is the cheapest thing in the canteen except steamed buns, only two yuan a cup. When I was in middle school, the milk tea there was at least three yuan. But the problem is that everyone later understood why the milk tea in the canteen is so cheap-a chemistry student (I don't know his name, just call it "Xiaohua") found that the canteen mixed at least 20% flour in the milk powder of bubble tea. So no one drinks milk tea anymore, so the canteen has to subsidize the workers with children with milk powder mixed with flour. No one really wants pearls, but it's a pity to throw them away, so they are copied into the dishes. Later, it was found that people who went to the self-help area only picked cabbage and tofu, and there was always a big basin of pearls floating in the soup like tadpoles when the canteen was closed. -everyone is afraid that there is something mixed in the pearl. Later, the canteen only sold this dish in the set meal area and bought a voucher of 50 cents back-however, the voucher can only be used to buy cabbage and tofu. In fact, there is nothing mixed in the pearl. Pearls were originally made of flour, sucrose and some tackifiers. There is nothing to mix except glue, which is more expensive than tackifier. Because I know this, I feel safe and bold to eat tofu stewed with cabbage and pearls. As it turns out, I haven't eaten for over a month. After the "flour incident", not only the students who drank bubble tea felt depressed, but even the canteen owner felt wronged. He personally told the canteen master that he could only mix 10% flour at most. But even if he feels aggrieved, he can't make an announcement saying-"Some students said that our bubble tea was mixed with 20% flour, but in fact I only mixed 10%. I hereby announce that please feel free to drink. " Although the experimental data has some deviation, it is not so outrageous. In fact, his data is more accurate. And the other 10% flour was mixed in before the milk powder factory left the factory, and the owner of Obana canteen didn't know about it.

As mentioned earlier, Xiaohua said that at least 20% flour was mixed in the milk powder. Although we all know that starch turns blue when it meets iodine, the difficulty lies in how to quantitatively measure how much flour is mixed-if only flour is mixed, perhaps the canteen owner will argue that the flour was accidentally sprinkled in, and the bath water will be used to make milk tea in order to save costs in the future. Bath water is a well-known mixture. Moreover, the chemical composition of bath water is very complicated, and it is quite difficult to find strong experimental data to support it. As for the experiment of determining the concentration of flour solution, you may think of adding excessive iodine solution into it, and then comparing the color of the solution with something similar to a pH color chart to determine the concentration of starch. But in fact, the commonly used colorimetric card in chemistry is only used to measure pH value, and the colorimetric card for measuring how much flour is mixed in milk powder has not been invented. Micro-attempts have been made to several sets of experimental devices, one of which is to determine the poor quality of iodine before and after the reaction by using the characteristic that iodine is easy to sublimate, but it failed later, because iodine and starch did not really react to generate new substances, but iodine molecules were attracted by hydroxyl groups on α -glucose molecules and embedded in starch spirochetes. This inclusion compound is very unstable, and money has been decomposed at the temperature of iodine sublimation-if you have studied physical chemistry (not physical chemistry here, physical chemistry is a branch of chemistry), you will know that van der Waals force is several orders of magnitude smaller than the interatomic force. Finally, he used enzymatic hydrolysis to hydrolyze starch into disaccharide with α-amylase, then processed it into monosaccharide with hydrochloric acid, and finally titrated it with potassium permanganate, bringing the experimental data into a formula that no one could understand even if it came out.

In fact, α -amylase is an elegant statement. More precisely, he vomited a few mouthfuls into the bath pot, and it was salivary amylase that catalyzed starch decomposition. So when he informed everyone, he said "at least 20%" instead of "20% floating up and down by 0.5". Up and down 0.5 is the maximum allowable experimental error, but he doesn't know if he has reached it. In fact, this experiment is very simple and only meets the standards of high school students. However, the result given by the experimental teacher is indeed A, on the grounds that "I study hard and am good at observation, which closely links chemistry with life and has caused good and extensive social effects." Hearing this, you may think that this teacher has had milk tea in the canteen before, but it is not. He never drinks milk tea in the canteen except when he is with his girlfriend (obviously, he doesn't drink milk tea in the canteen when he is with his girlfriend). He has just applied to join the party, and intends to write this as a typical story of students' ideological work in the application materials.

(3)

The teacher is right. Small-scale experiments have had a wide social impact. If he just stays in the laboratory to do experiments and gives the experimental report directly to the teacher after finishing, it won't have much influence. He will definitely not get an A, but it will be good to pass. In fact, after he finished the experiment, he went to the triangle with the experimental report. Anyone who knows our school knows the triangle. This is the assembly place of schools and even cities. Every weekend, all kinds of people gather here-anti-Japanese, protesting against the boss's failure to pay overtime, immigration consultation, performance art, accusing the war, memorizing English texts, practicing qigong, buying CDs, and drawing boards to arouse students to boycott the garage where bicycle tires can't be replaced for a week.

Here, I want to make it clear that the triangle and a canteen are on both sides of the school, separated by a road. It is conceivable that Xiaohua delivered a short speech for 20 minutes, and then the protest team flooded in the direction of a canteen, causing traffic jams for more than half an hour. You already know the rest. The milk tea in the canteen can't be sold, so we have to fry it in stewed tofu with cabbage. When he went to Xiaoshi, it was just an experimental report. On the way, a follower printed a pile of leaflets for him and the person in front, so that Xiaoshi finally sent out the experimental report as a leaflet and had to do the experiment again. Of course, the teacher didn't know this, so he said "study hard" in his comments. After shouting slogans at the entrance of the canteen, the team was divided into several groups and scattered in all directions of the campus. Dozens of leaflets were stuffed as soon as people met. I happened to meet this spectacular scene-I was about to pick up Wang Qian from the girls' dormitory in the opposite campus, and I saw a dark team coming on the way. When I reappeared after being submerged by the flood in line, I happened to have dozens of leaflets in my hand. This kind of leaflet is made of 70g A4 paper, and its quality is very good. Only print one side, and you can mow the back. Write it with a pencil and then with a ballpoint pen. I stuffed these dozens of leaflets into my schoolbag. After a while, another team came, and then I took dozens of leaflets in my hand. At this moment, I thought, I don't know how many more teams I need, so I took all the leaflets in my hand and occupied them with both hands. They will never send me flyers again. Sure enough, several teams passed by, but the number of leaflets in my hand didn't increase because they couldn't fit them if they wanted to.

I walked downstairs to Wang Qian's dormitory with more than 100 leaflets. One of the people on duty at the entrance of this dormitory building is called Teacher Extinction. In fact, she is not old enough to be a teacher, but a middle-aged woman in menopause. But I guess her quality of life must be good. Wang Qian once told me secretly that she heard the sound of extinction, which sounded like a sow being slaughtered.

It is not easy to pass through the door of extinction. You should at least prepare a wig, lipstick and mascara, and then ask your girlfriend to buy a girl's dress. You should also add a bra with a sponge in summer, because steamed bread is too expensive to be reused. Therefore, almost all the boys with girlfriends in this building have at least one bra, and some boys are too lazy to wash it, and they have to wipe their sweat after playing the ball. My knowledge in this field was taught by a senior. He also said that fake foam should always be put into conditioner, otherwise it will dry quickly, and it looks like a roll of kelp when worn on your head from behind. And when you walk through extinction, you must relax, don't walk too fast, don't walk too slowly, and don't talk, but even so, I haven't shaved for half a month because I forgot to go in, and I was found again.

So I wisely chose to wait for her at the entrance of the dormitory this time. If you are curious about where we are going, I might as well tell you. Everyone has everyone's romance, and our romance is to visit this city ten times bigger than the place where we used to live by bike. When we first started dating, we agreed to take one day out for cycling every weekend until we traveled all over the city. I have a map. She painted the road where we rode hand in hand. Now this map is colored. I also told her that we would use this map as the background of our wedding photos when we got married in the future. That's her and me sitting in the shade of Fuxing Park. She smiled and raised her hand to hit me. "Go to hell, who will marry you!" "

I planned the whole day's trip in my mind and looked inside the dormitory. Teacher extinction is sitting in the middle of the dormitory door, holding a chair and a dozen newspapers, just like a yellow traffic line. Everyone who enters the dormitory passes by her right, and everyone who leaves the dormitory passes by her left. I was thinking about my own affairs in a daze when a beautiful girl who had never met me came over and extended her hand to me. I didn't react. "What?" "Give me the flyer you sent." Only then did I know that I stood here with more than 100 leaflets for so long and was busy stuffing these performance papers into my schoolbag. The girl walked away and whispered to her companion, "Unlike leaflets, she secretly stood at the door of the girls' dormitory." I swear, I'm not blushing at all It's true. Forget it if you don't believe it

(4)

I told you a story before. The bubble tea in the canteen is very cheap, and everyone is rushing to buy it. After in-depth research and experimental design, it was found that milk tea was mixed with flour, so it was reduced to a triangle to make the news public. After a storm, the tea making in the canteen was no longer interested. Later, everyone went out with a small bottle of iodine. After buying the foamed tea, they poured a little. If iodine drops into it and turns blue, they take out the shopkeeper and criticize him. Some people also sealed a pinch of flour with wax pills. After dropping a few drops of iodine, the milk tea suddenly turned dark black like purple potion. Naturally, he could mobilize everyone to smash the shop, and then moved the beverage machine back to the dormitory to make his own milk tea while others were not paying attention.

At this point, the story is coming to an end, but some people may still have doubts. How did Xiaohua discover that milk tea was mixed with flour, and then designed such a rigorous experiment to determine the flour content? Maybe you think, as his teacher said, he is good at linking chemistry with life, but he is not. He came across this thing by accident. Or you might think that one day the canteen master mixed too much flour and he noticed. Actually, it's not. The canteen owner has long noticed this. In addition to requiring canteen chefs to mix milk powder with milk powder, they are also required to add a lot of saccharin to the fruity powder. Therefore, when drinking milk tea, you will only drink a heavy sweetness, and you will feel that the canteen is particularly willing to give up fruity powder.

When I was writing the third chapter, Wang Qian sneaked into my dormitory and stared at me at my desk, so I had to add extinction and our affairs in the second half of the third chapter. Actually, those things have little to do with milk tea, but Wang Qian said that she likes that paragraph best. When she came in, she grabbed my notebook, read the first two chapters I wrote, and then frowned at the chemical experiment step: "You said it was interesting?" This kind of thing is only interesting for you boring science students. "She insisted that I write down the part that was used as a leaflet. She said it was interesting, but I didn't want to, because if my friends saw it, it would make me lose face. He said, "Are you going to write or not? If you don't write, I'll make trouble with you here so that you can't write anything! "

Wang Qian went to wash apples, so I had a chance to write the above passage. We can continue to talk about why Xiaoshi found flour mixed in milk powder. As I said, it happened by accident. I didn't tell you he had a girlfriend, but he did, and he was pretty. At this time, Wang Qian came in with two red apples and curled up in a chair. When he saw this, he asked me, "Do you think his girlfriend is beautiful or I am beautiful?" I said, "You are beautiful, okay?" She screamed, half laughing. "Really?" I said, "Really, really, don't interrupt, you let me finish."

So, why did Xiaohua find that milk tea was mixed with flour? This happened completely by accident. He has a girlfriend, but not as beautiful as Wang Qian. This matter has something to do with his girlfriend. As you already know, Xiaohua, a student of chemistry department, has been exposed to all kinds of chemicals and has been affected by drugs such as sulfur dioxide, hydrochloric acid vapor and formalin for a long time in the laboratory. Xiaohua has been completely harmless. Xiaohua often stays in the laboratory, so the laboratory teacher made an exception and gave him a key to stay as long as he wanted. Generally, by nine o'clock in the evening, everyone else in the lab has finished, leaving only one person, which provides convenience for him and his girlfriend-in fact, this is the real reason why Xiaohua likes to stay in the lab. Every night at 9: 30, his girlfriend goes to his lab. Sometimes they will go out to eat snacks arm in arm, and sometimes when they are young, they will lock the door of the laboratory from the inside, leaving only two lights for their girlfriends to sit next to his voice. As mentioned above, there are various odors in the laboratory, such as sulfur dioxide, volatile hydrochloric acid, chlorine gas, and the stench of protein after being oxidized and dehydrated by sulfuric acid. Although Xiaohua is completely harmless, his girlfriend can't stand it, so when his girlfriend came to the lab that day, he pulled the ventilation pipes on the surrounding test bench to the longest, all at them. So those ventilators look like people with long necks, curious to see how their lips don't stick together.

You can imagine what will happen next. In short, when they open their eyes and look at each other again, they all want to see aliens. Xiao Hua saw that his girlfriend's mouth, face, eyelids, neck and ears were all large pieces of blue and purple. You should have guessed how this kind of thing affected the atmosphere, so they did nothing later. You don't have to use too much pen and ink in the future. I can't read it when I go back. Just call his girlfriend and ask her what she had eaten before she came that night. She told him that she had a cup of milk tea in the canteen. Then hush remembered that he wiped the burning bubbles in his mouth with iodine in the laboratory in the afternoon, which caused a mysterious chemical reaction between milk tea and iodine on his lips and mouth. Then hush did something, and the products of the reaction almost spread to his girlfriend's whole face and neck. This is the whole thing, and then, you already know. Also, if you have seen the mixed color of starch and iodine, you won't feel too ugly, because even if you paint it all over your face, you will only be considered as a fan of the French team at most. However, we all know that girls love to dress up, and lip gloss, foundation and other necessary equipment are essential. These things are red and beautiful, but they are not so beautiful when mixed with blue starch iodine complex. You can mix red ink and blue ink at the ratio of 2: 1 to see what color it is. Now I can tell you that it is very close to the color of that beautiful girlfriend's face. She was not as beautiful as Wang Qian at that time.

At this point, Wang Qian said, well, you've written enough. You can go shopping with me. If I say let me write for a while, she will definitely say that it is cheap for you to write for so long, so I have to let this article come to an end. I understand that on my map, the whole Nanjing Road from People's Square will be heavily painted with crayons. If she is in high spirits, Huaihai Road and Xiangyang Road are also essential-these places have almost been erased on the map.

(5)

Finally, in the experiment of determining starch mass fraction, there is still one thing that needs to be added, that is, before the experiment, the bubble tea should be filtered through a semi-permeable membrane made of egg white for several times, otherwise the glucose component in the bubble tea will be included in the final determination of reducing sugar, which will make the experimental result on the high side-considering that there is a certain proportion of protein and fat in flour, it is more complicated, so we should go out first to ensure the experimental accuracy. I wonder if Xiaoshi has considered this. Anyway, he no longer goes to the lab to kiss his girlfriend every day, because he became the president of the student union because the teacher of the Youth League Committee drank milk tea in the canteen. But his experimental teacher didn't join the Party in the end, because the canteen owner is a relative of the Party secretary. But these things have nothing to do with me.

This is the end of the story. A canteen may never sell milk tea again. Later, fewer and fewer people went to the school cafeteria to eat, so the bookstore and book bar at the school gate opened into restaurants, and business was booming. Everyone in school is eating better and better. In the afternoon, I can always hear hiccups everywhere in the first class. However, I sometimes miss the time when a canteen sold milk tea. I remember not long after I met Wang Qiangang. We often ate in a quiet corner there and chatted one by one. I often saw her face with strands of hair smiling as red as an apple on a tree. One day, she toasted me with that cup of milk tea mixed with 20% flour. The liquid in the plastic cup reflects the midday sun and looks dazzling. After drinking milk tea, she cocked her little head and stared at me naughtily and asked, "Do you love me?"