几道英语题,大家帮忙解析一下

几道英语题,大家帮忙解析一下
1. the goods_____when we arrived at theairport.
Awere just unloading B had just unloaded
C were just being unloaded D were just beenunloaded
2.the wind _____heavily last night.
A blew B was blowing C has blown D had blown
3.i am going to stop this now i _____
Abore to dieB am boring to death Cbore whit death D am bored to death
4.the question _____at present is of great importance.
A to be discussed B discussed
C being discussed D to discuss
5.they found the lecture hard_____.
A tobe understandB to understand
C for understanding D to have been understood
详细解析,不胜感激!