Great changes___ in the past ten years in China.
A. took place B. have taken place C. were taking place D. had taken place
You can't use the computer, it____.
A. was broken down B. is wrong C. is bad D. has broken down
Lookout, please keep away from the fire, or your trousers will__
A. burnt B. burn C. burning D. get burn
请给出答案并解释