几道英语题,大家帮忙解析一下

1. the goods_____when we arrived at the airport.
Awere just unloading B had just unloaded
C were just being unloaded D were just been unloaded
c,被动语态,句型be doing when.
2.the wind _____heavily last night.
A blew B was blowing C has blown D had blown
a,last night 过去时
3.i am going to stop this now i _____
Abore to die B am boring to death Cbore whit death D am bored to death
d,固定短语
4.the question _____at present is of great importance.
A to be discussed B discussed
C being discussed D to discuss
c,doing 作定语,正在讨论
5.they found the lecture hard_____.
A to be understand B to understand
C for understanding D to have been understood
b,to do 作状语