条件状语从句练习题难度比较简单的那种.最好有答案.

1.I’ll lend you my car _______ you return it intact.
A.so far as B.as long as C.unless D.until
2.We are going to have a barbecue _______ it rains .
A.if not B.when C.except that D.unless
3.Eat less food _______ you want to put on weight .
A.if B.unless C.until D.as soon as
答案：CDB