____ I know they get off the airplane,I will no longer feel worried.

____ I know they get off the airplane,I will no longer feel worried.
A.While
B.Unless
C.As long as
D.Even though
囧，忘了说，答案是c，为什么？

I don't know the man ____ siting there With what ____ the car is ____ I want to know.选择A.to fix; what为什么？ I know the boy ____ our teacher is talking. A.who B.to who C.to whom D.to that I donnot know the answer - ---the question. 【在线~！！！】Do you know the reason ____ he was late? I like ____(rain)all the time?????????? 选择：Hello!Tom ----- I'm sorry,____ I don't think I know you! I like the house ___ I used to live ____. I didn"t hear the ring,I ____ asleep. The woman might know the strange events,____(不是吗）？