The picture shows the pattern of digestive system. Please answer the following questions according to the analysis of the picture. (1) The order of food passing through digestive organs is: (Please use numbers and arrows. This picture is a schematic diagram of the digestive system of human body, and each structure in the picture is: 1 oral cavity; 2 esophagus; 3 stomach; 4 pancreas; 5 large intestine; 6 small intestine; 7 anus; 8 salivary glands; 9 pharynx; 10 liver; 1 1 gallbladder; 12 duodenum; 13 cecum; 14 appendix

(1) The digestive tract includes the mouth, pharynx, esophagus, stomach, small intestine, large intestine and anus. The order of food passing through the digestive tract organs is: 1→9→2→3→6→5→7.

(2) The digestive tract includes oral cavity, pharynx, esophagus, stomach, small intestine, large intestine and anus. There are salivary glands, gastric glands, liver, intestinal glands and pancreas, among which 8 salivary glands, 10 liver and 4 pancreas are located outside the digestive tract, and intestinal glands and gastric glands are located inside the digestive tract. Therefore, digestive glands can be divided into two types: those located outside the digestive tract and those located in the digestive tract. Salivary glands secrete. The liver secretes bile, which does not contain digestive enzymes, but can emulsify fat, emulsify large fat particles into small fat particles, and physically digest fat; Pancreas secretes pancreatic juice, which contains pancreatic amylase, pancreatic maltase, trypsin, pancreatic lipase, etc. Therefore, pancreatic juice secreted by pancreas contains the most kinds of enzymes.

(3) The small intestine contains a variety of digestive enzymes, which can digest starch, fat and protein. Most of the digested products are absorbed in the small intestine, so the small intestine is the main place for digestion and absorption. The first section of the small intestine is about twelve fingers long, so it is called 12 duodenum.

So the answer is:

（ 1） 1→9→2→3→6→5→7

（2）8； Salivary gland; 10； Liver; 4； Pancreas; Saliva; Bile; Pancreatic juice; 4； Pancreas; Pancreatic juice;

（3）6； Small intestine; ? 12； ? Duodenum.