题目内容：

1.No matter ___________the CRH accident in Wenzhou,it had and will have much warning significance.
A.how the investigators said caused
B.what the investigators said caused
C.why the investigators said caused
D.the investigators said how caused
2.--Are you going to stay overnight?
--Not ____it's absolutely necessary.
A.unless
B.when
C.until
D.if
3.Love is ______Mummy sees Daddy smelly and sweaty and still says he is more handsome than David Beckham.
A.that
B.how
C.when
D.since
4.Many pregnant women have bought this kind of clothes to __________radiation.
A.block
B.protect
C.distinguish
D.guarantee
5.The happiest people are not those __________have the best of everything,but _______make the best out of everything.
A.who,that
B.who,who
C.that,who
D.that,that