Questions 11 to 18 are based on the conversation you have just heard.

A．He should have the right diet.
B．He should eat less to lose some weight.
C．No medicine could solve his problem.
D．He was ill because he always ate too much.

A．The graduate students could understand the French lecture.
B．The undergraduate students could understand the French lecture.
C．The undergraduates couldn’t understand the lecture while the graduates could.
D．Neither the undergraduate students nor the graduates could understand the lecture.