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

A．Manager and clerk.
B．Director and secretary.
C．Doctor and nurse.
D．Professor and student.

A．Young birds and young bats must be taught to fly.
B．Elephants do not seem to know file function of their trunks.
C．Thousands of young seals drown every year.
D．Older harvest mice build better nests than beginners.