16.The time has come ___________ we can make extensive use o

16.The time has come ___________ we can make extensive use of nuclear energy.
A.as B.when C.while D.since
17.After I had graduated,I continued to ________ myself to research.
A.contribute B.reduce C.devote D.conduct
18.A miner works underground,digging out ________ such as coal,copper,and diamonds.
A.mines B.miners C.minors D.minerals
19.The border police __________ the traveler to unlock his luggage.
A.required B.requested C.asked D.begged
20.A teacher cannot __________ it for granted that students always do their homework.
A.make B.think C.take D.consider
21.You will need to seek ___________ advice about your claim for compensation.
A.progressional B.productional C.professional D.provisional
22.Beer has a very __________ smell; it’s quite different from the smell of wine.
A.different B.distinctive C.distinct D.differing
23.As a result of the accident,the child was __________ to the house for six weeks.
A.confounded B.conditioned C.condemned D.confined
24.If they have ___________ to the system,they can even complete the form electronically through the internet.
A.right B.power C.access D.key
25.In practice,___________ to the universities is competitive.
A.entrance B.to entering C.to enter D.entry
26.Even though pay was important,___________ brought the greatest satisfaction was knowing that someone had noticed how a job was being done.
A.what B.who C.which D.that
27.The atmosphere is all the air ____________ the earth.
A.surrounds B.surrounding C.to surround D.is surrounding
28.She won’t leave the TV set,___________ her husband is waiting for his supper.
A.as if B.even if C.so that D.just as
29.John last saw Bill in high school and hasn’t seen him ____________.
A.never since B.ever since C.any more after D.yet after
30.The class began with ten students,but several ___ _____.
A.fell out B.stopped out C.dropped out D.felt out

16 A.
17 C.
18 D.
19 A.
20 A.
21 C.
22 B.
23 B.
24 C.
25 A.
26 C.
27 A.
28 B.
29 C.
30 C.