THE DIGESTTVE SYSTEM
When you’re hungry and you smell dinner, your mouth waters. This is the first step in changing the food you eat into the kind of food that cells can use. This change is called digestion and it begins in the mouth.
Suppose you are eating sandwich. Your front teeth cut and tear the sandwich. The molars grindit. Saliva, the juice in the mouth, gets everything moist. Saliva also contains a type of chemical called an enzyme. It starts breaking down the starch of the bread into sugar.
The moist ball of the food is carried to the back of the mouth by the tongue. Muscles force the food into the esophagus, a narrow tube behind the windpipe. Other muscles force the food down the esophagus. They do their work so well that the food would travel along even if the person were doing a headstand.
Although a person does a headstand, the food that he eats…
A. is carried back to his mouth from his stomach
B. stays in his mouth
C. pushes from his stomach to his mouth
D. still moves from his mouth to his stomach
E. stays still in his stomach
Jawabannya Adalah : D
