10. Great as Newton was, many of his ideas ?____? today andare being modified by the work of scientists of our time.?

A. are to challenge

B. may be challenged?

C. have been challenged

D. are challenging?

11. It is necessary that the students ?____? more excercises todo.?

A. have

B.must have

C. will have

D. can have?

12. The present situation forced us to ?____? this policy.?

A. adapt

B. admit

C. adopt

D. adjust?

13. We can ?____? the two islands with a bridge.?

A. unite

B. connect

C. relate

D. combine?

14. Due to the bad weather the plane was ?____? for two hours.?

A. delayed

B. canceled

C.postponed

D. dismissed?

15. The ?____? populated area was a breeding place forinfectious diseases.?

A. densely

B. sparcely

C. improperly

D. poisonous?

16. Perhaps the customer has ?____? his monthly statement and not paid the bill.?

A. omitted

B. bewildered

C. overlooked

D. escaped?

17. He was almost asleep, ?____? with all this hard work.?

A. worn down

B. worn out?

C. worn off

D. worn away?

18. It happened in front of a fruit and vegetable ?____?in myneighborhood.?

A. station

B. stand

C. joint

D. lift?

19. The first step in the study of any language is observing and?____? precisely what happens when native speakers speak it.?

A. setting off

B. setting about?

C. setting up

D. setting down?

20. As the pressure?____?, the liquid rock is forced up through channels in the resistant rock tothe earth’s surface.?

A. intensifies

B. magnifies?

C. heightens

D.deviates?