A beautiful picture ____ the children in the classroom.
A. was shown to B. was shown C. were shown to D. were shown
People have come to know that their health must ______.
A. pay more attention B. pay more attention to
C. be paid more attention D. be paid more attention to
（题文）Many books on science _____ since I went to college.
A. were bought B. have been bought
C. will be bought D. are bought
The sick girl _______ to the hospital at once.
A. must send B. be must sent C. must be sent D. be sent
The window of our house _______ once a week.
A. have been cleaned B. is cleaned C. are cleaned D. are cleaning
When ______ your school ________?
A. did, built B. was， built C. is， built D. was， building
