It was ten o’clock _____ he came back.
A. that
B.when
C.so
D.which
You can stay here _____ you keep quiet.
A.as long as
B.unless
C.case
D.in order
The engineers are so busy that they don’t have time for outdoor sports activities, ______ they have the interests.
A.wherever
B.whenever
C.even if
D.as if
After the earthquake， a new school building was put up _____there had once been a theatre.
A.that
B.where
C.which
D. when
_____ difficulties we may come across，we will help one another to get them over.
A. Whatever
B. Whichever
C.However
D. What
_____ , he couldn’t earn enough to support the family.
A. Hard as he worked
B.As he worked hard
C. As hard he worked
D. Hard as did he work
He＇ll never succeed in passing the CET-6，_____ hard he tries.
A. however
B. whatever
C.despite
D. though
Great _____ the difficulties are，we must do our best to succeed.
A.while
B.as
C. although
D.however
We must begin testing this instrument, no matter _____ difficult it is.
A. however
B. how
C.whatever
D.what
_____ , the old man had a sharp ear for even the slightest sound.
A. As he was blind.
B.As blind as he was
C. Blind as he was
D.As he was just blind