-Is Jack on duty today?
-It ____ be him. It’s his turn tomorrow.
A.mustn’t | B.won’t | C.can’t | D.needn’t |
—I wonder why Tom left without a word.
—He __________ have had some trouble, for he looked dull.
A.should |
B.must |
C.can |
D.could |
I had just got up and was about to cook my breakfast__________ the telephone rang, but it was hung up __________ I could answer it.
A.while ; when |
B.when ; as |
C.as;after |
D.when;before |
Swimmers must be very strong in order to build up speed because of the high resistance (阻力)of the water. Runners,__________, must struggle against the heavy resistance of the air and ground.
A.generally |
B.similarly |
C.naturally |
D.probably |
They're not playing baseball today __________ the rain.
A.because |
B.as |
C.since |
D.because of |
In some places women are expected to earn money __________ men work at home and raise their children.
A.but |
B.while |
C.because |
D.though |