21.

　　A) He doesn't know where his brother keeps his computer.

　　B) The woman should buy a used computer.

　　C) He doesn't know how much computers cost

　　D) His brother paid too much for the computer.

　　22.

　　A) The doctor can see the man this week.

　　B) Appointments must be made two weeks in advance.

　　C) The man should call back on Friday.

　　D) The doctor canceled his appointments on Friday.

　　23.

　　A) He started the semester in a bad mood.

　　B) He's not usually bad-tempered.

　　C) He has few responsibilities.

　　D) He doesn't like the man.

　　24.

　　A) He might go to the movies when he finished studying.

　　B) He doesn't know if he can concentrate on a movie.

　　C) He needs to stop studying for a while.

　　D) He can't think about anything but studying.

　　25.

　　A) He forgot to cancel the reservation.

　　B) They can go to the restaurant after the woman has finished working.

　　C) He has to work late tonight.

　　D) They don't have a reservation at the restaurant.