The boy the teachers considered ______was caught _____ in the exam, which surprised us very much. [ ]

A. to be the best; cheating

B. as the best student; to cheat

C. to have been studied well; cheating

D. as a good student; to cheat

用来衡量桥梁结构整体刚度的主要指标是（）。

A.动力冲击系数

B.加速度

C.动位移

D.静位移