单项选择题

Since many insects have already become（）to DDT, scientists have to look for some new insecticide

A.active
B.resistant
C.tough
D.gradual

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His parents no longer worry about him. He has a good jo...

单项选择题His parents no longer worry about him. He has a good job and can live（）his own now.

A.at
B.by
C.on
D.with

He（）the medicine quickly and then drank some orange jui...

单项选择题He（）the medicine quickly and then drank some orange juice.

A.sucked
B.swallowed
C.licked
D.digested

While studying he was financially dependent （）his wife....

单项选择题While studying he was financially dependent （）his wife.

A.to
B.of
C.on
D.from

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