--- Jack fell off the ladder yesterday，but he is all right now.  ---What a lucky dog! He ________himself badly. 

—How did your mathematics exam go？—I thought I           ，but in fact I fell behind in the class.

_______  it be true that the road is being blocked at this moment, for cars are moving like snails inch by inch

These achievements_______ without the contribution of Qian Xuesen, a key leader of the New China's nuclear, missile and so on．

But for those interruptions, the meeting _____ half an hour ago.