I didn’t see your sister at the meeting. If she __________, she would have met my brother.

A．has come

B．did come

C．come

D．had come

各种收缩时产生张力大小的顺序依次为（）

A.向心性收缩＞等长收缩＞离心性收缩

B.向心性收缩＞离心性收缩＞等长收缩

C.离心性收缩＞等长收缩＞向心性收缩

D.离心性收缩＞向心性收缩＞等长收缩

E.等长收缩＞向心性收缩＞离心性收缩