1.We must do it well, ________there are a lot of difficulties.
A.as if
B.as though
C.even though
D.even as
2.________ difficult it may be,we are sure to stick to our principle.
A.How
B.No matter how
C.What
D.No matter what
3.—It’s a long time__________I saw you last.—Yes,and what a pity it is now that it will be a long time__________we see each other again.
A.before;since
B.since;when
C.since;before
D.when;before
4.—Why didn’t you try your best to get on the bus?—I tried to,but_________ I could,it started moving.
A.until
B..when
C.before
D.after
5.The head of the company promised to deal with matters of this sort________ he returned to his office.
A.until
B.while
C.by the time
D.the moment
6.—Did you remember to give Tom the key to his bedroom?—Yes.I gave it to him________ I saw him.
A.while
B.once
C.suddenly
D.the moment
7.He had already walked three or four miles_______ he saw a cart,half-full of hay,by the side of the road.
A.while
B.when
C.the moment
D.unless
8.My grandpa sowed the flower seeds in the garden_____________ it was the best time for them to grow.
A.where
B.when
C.that
D.until
9.I’d like to settle down somewhere_____ the climate is mild and the sun shines all year long.
A.which
B.that
C.where
D.when
10.Heat does not travel by connection in solid,because the solid does not move, _____.
A.so does a liquid
B.so a liquid does
C.as does a liquid
D.so is a liquid