Answer:
Each statement represent a stage of the human digestive system. The first two stages are part of the cephalic phase.
Salivary amylase refers to the breakdown of food by enzymatic action. Saliva can be considered as the first reaction to food, it can be produced by just seeing or smelling food, this saliva is what contains enzymes to start breakdown food. People don't know that digestion already begins in the mouth.
During chewing, the teeth break down food into smaller pieces, during this stage is produced the bolus, which is swallowed to enter the stomach.
Next, during the gastric phase, enzymes break down food into molecules. The gastric acid does its job to pass the result to the duodenum.
Then, once is placed in the duodenum, the third stage begins, the pancreas produces a number of enzymes that breakdown food furthermore. After that, the food passes to intestines to absorb nutrients and the waste is defecated through the rectus.
