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

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

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

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

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

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

单项选择题The water was so（）that we could see the fish inside clearly.

A.transparent
B.obvious
C.apparent
D.visible

单项选择题As I had earlier made up my mind to run for governor, I could not（）I must go on with the fight.

A.vary
B.withdraw
C.undergo
D.discard

单项选择题The medicine the doctor gave me（）my headache.

A.reduced
B.improved
C.released
D.relieved

单项选择题Many people save money to（）for their old age.

A.supply
B.offer
C.provide
D.yield

单项选择题Being named the best athlete of the year was an important（）in the baseball player’s life.

A.segment
B.ingredient
C.contribution
D.episode

单项选择题The swimming pool is so（）that it's safe for small children.

A.stable
B.smooth
C.superficial
D.shallow

单项选择题Stone does not（）, and so the tools of long ago have remained when even the bones of the men who made them have disappeared without trace.

A.crack
B.decay
C.destroy
D.crush