主动语态原句：Wild fires destroy many forests.一般现在时：Many forests ________1_________ by wild fires.现在进行时：Many forests ________2_________ by wild fires.过去完成时：Many forests ________3_________ by wild fires.

主动语态原句：The teacher answers the students' questions.一般现在时：The students' questions ______1_________ by the teacher.过去进行时：The students' questions ______2_________ by the teacher.现在完成时：The students' questions ______3_________ by the teacher.

The book________ by Jennifer by the end of last month.

A. have finished
B. finished
C. have been finished
D. had been finished

A stylish bike was bought ________ me by my parents as a birthday present.A. to B. for C. by D. on

A. to
B. for
C. by
D. on

A stranger ________ walk into the building.

A. has seen to
B. was seen to
C. has seen
D. was seen

I _______one day to decide whether I should accept this invitation.

A. give
B. gave
C. has given
D. was given

The movie star _______everything before he went out of the hotel

A. had been told
B. has told
C. has been told
D. is told

Great changes_______in my hometown during the past 20 years.

A. were taken place
B. have been taken place
C. have taken place
D. taking place

The milk________to each house before 7∶00 every morning.

A. send
B. should be sent
C. will send
D. has been sent

No one likes_________ in the public.

A. to laugh at
B. laugh at
C. been laughed at
D. being laughed at