一．选择题（真题回放）
1.He fall of the tree.
A. was seen to B. was seen C. saw to D. saw
2.An accident last night.
A. was happened B. happened C. happens D. is happened.
3.Great changes in our city since 19e 80.
A. took place B. have taken place C. were taken place D. have been taken place.
4.Students to close the windows before they leave the physics and chemistry lab.
A. tell B. will be told C. was inviting D. invited