31.Doing your homework is a sure way to improve your test scores, and this is especially true _____ it comes to classroom tests.
A.when
B.since
C.before
D.after
32.Don't worry.The company will _____ all your expense.
A.satisfy
B.meet
C.pay
D.submit
33.Eventually, people spread throughout the continent, ______ the entire species.
A.wiping out
B.wiping away
C.wiping off
D.wiping up
34.Experts say walking is one of the best ways for a person to ______ healthy.
A.preserve
B.stay
C.maintain
D.reserve
35.Faced with the ______ difficulties, they are determined to carry on their program.
A.satisfactory
B.attributable
C.innocent
D.intangible
36.Fewer and fewer of today's workers expect to spend their working lives in the same field, ______ the same company.
A.all else
B.much worse
C.let alone
D.less likely
37.Flying in an airplane was once thought to be an impossible ______.
A.task
B.profession
C.promise
D.contest
38.Fresh vegetables are straight from the ______ and raw vegetables are ______.
A.earth...cooked
B.soil...uncooked
C.floor...cooked
D.ground...uncooked
39.From this material we can _____ hundreds of what you may call direct products.
A.derive
B.discern
C.diminish
D.displace
40.Fruit is cheapest _____ season.
A.at
B.on
C.in
D.through