(1) According to the diagram of the Balanced Dietary Pagoda, it can be seen that the food of the first level of the Balanced Dietary Pagoda is rice, bread, potatoes and other foodstuffs, and the main nutrient is starch. The digestion of starch begins in the mouth, the salivary amylase enzyme is broken down into maltose, in the small intestine under the action of pancreatic and intestinal fluids are completely broken down into glucose.

(2) From the above table, we can see that bleeding gums is caused by the body's lack of vitamin C disease. By the "Balanced Diet Pagoda" can be seen, the need to supplement the second level ② layer of food, because rich in vitamins and inorganic salts, vegetables, fruits more. The body's large intestine and small intestine can absorb vitamins.

(5) fried chicken wings, braised fish, chicken thighs, milk have fat, protein, lack of vitamins, sugars and other substances. According to the tips of the Dietary Pagoda, "Balanced Dietary Pagoda" the first level ① layer is rich in sugar-containing foods, the second level ② layer is rich in vitamins and inorganic salts of vegetables and fruits. Therefore, Xiao Qiang's recipe obviously lacks the foods in the ① and ② levels.

So the answer is: (1) starch; mouth; amylase; maltose; small intestine; glucose.

(2) ②; large and small intestine;

(3) ①; ②.