31.All science students,______,should have a good foundation

31.All science students,______,should have a good foundation in basic sciences.
A.whether they are future physicists and chemists
B.they are future physicists of chemists
C.they should be future physicists of chemists
D.be they future physicists or chemists
32.______ convincing an argument is,it needs support of evidence.
A.Whatever
B.However
C.Although
D.Even if
33.______ give him a chance to try?
A.Oughtn’t to we
B.Oughtn’t we to
C.Ought to we not
D.Oughtn’t we
34.Three hours ought to be enough time,______?
A.oughtn’t three hours
B.didn’t they
C.shouldn’t it
D.shouldn’t three hours
35.You must follow the directions exactly and if you become ______,you must take the time to go back again and reread them.
A.to confuse
B.confusing
C.confuse
D.confused
36.I’m sorry,but I had no alternative.I simply ______ what I did.
A.must do
B.had to do
C.ought to have done
D.have to do
37.Sound is conducted through steel in the same manner ______.
A.as in air
B.as through air
C.as air does
D.like air
38.Not once ______ his view of life.
A.did the gentleman mention
B.the gentleman mentioned that
C.the gentleman mentioned
D.does gentleman mentioned
39.You’d rather watch TV this evening,______?
A.isn’t it
B.hadn’t you
C.wouldn’t you
D.won’t you
40.Grace advised us to withdraw ______.
A.so as to get not involved
B.so as not to get involved
C.so that to get not involved
D.as not to get involved

31A,32B,33B,34C,35D,36B,37B,38A,39C,40B