A、The stale food he ate. B、The fruit juice he drank. C、Too much food he ate. D、The cold he got. A

M: I feel an abdominal pain and nausea.
W: Do you feel like vomiting?
M: Yes. I also have a slight fever.
W: How about your bowel movements?
M: Since this morning 1 have been passing loose and watery stools several times.
W: You are suffering from diarrhea. What did you eat yesterday?
M: I ate some stale bread and other food.
W: The food might have been contaminated with bacteria.
M: Can I eat or drink anything?
W: You should drink a lot of water and fruit juice. But do not eat for a day, so that your bowels will have a rest. If you eat, take small servings of soft, bland foods, such as porridge, cereal. Avoid large meals.
M: Should I take medication?
W: If your diarrhea is so frequent or watery as to cause inconvenience you can take some medicines as prescribed by the doctor.
M: Is diarrhea serious?
W: Yes, only when you get dehydrated or lose much body fluids. So you should drink freely to replace the salts and water.
M: What are the signs of dehydration?
W: The signs of dehydration are inelastic skin, dry lips and mouth, furred tongue. If you pinch up the skin on your arm or abdomen and let go, it sags back slowly.
M: Do I have to go to the clinic?
W: If your diarrhea persists for more than three or four days you should go to the doctor, especially when the stool is black and bloody. In your present case you don’t have to worry. Just take some medicine and replace the lost fluid.
Questions 16-20 are based on the passage you have just heard.
16. What is the woman’ s diagnosis of the man?
17. What might be the cause of the man’ s illness?
18. In order to recover soon, which of the following should the man avoid eating or drinking?
19. According to the woman, when should the man take medication?
20. What does the woman think of the man’ s condition?