1.Although Columbus knew the earth was round, he could not imagine ____.
(A) how was it large
(B) how large it was
(C) of what large it was
(D) of that what size
2. ____ in the stratosphere is depleted is not completely understood.
(A) How ozone
(B) While ozone
(C) Ozone
(D) Ozone that
3. It is believed ____ into modern birds.
(A) that pterosaurs evolved
(B) what pterosaurs were evolved
(C) it was pterosaurs evolved
(D) pterosaurs that were evolved
4. The fact ____ the forests of North America are shrinking almost as fast as are those of the Amazon Basin is largely ignored by the American people.
(A) of
(B) which
(C) is that
(D) that
5. The report ____ some birds guide African natives to honeybee hives was for a long time discredited by the scientific community.
(A) why
(B) which
(C) what
(D) that
6. Riding the rapids down the Colorado, Captain Powell was determined to prove ____ could be traversed.
(A) the Grand Canyon it
(B) that in the Grand Canyon
(C) how in the Grand Canyon
(D) that the Grand Canyon
7. She wouldn't tell me ____ she saw there.
(A) what
(B) that
(C) which
(D) how
8. Quantum physicists are interested in ____ tiny particles move.
(A) what
(B) which
(C) how
(D) that
9. ____ after lying dormant for hundreds of years is hard to believe.
(A) It is seeds that can sprout
(B) Seeds can sprout
(C) That seeds can sprout
(D) Sprouting seeds
10. Whether she can do the job depends on how well prepared ____.
(A) is she
(B) can she
(C) she is
(D) she can
11. After comparing the two answer sheets, the teacher came to the conclusion ____ in the exam.
(A) is the students cheated
(B) which is the students that cheated
(C) that the students cheated
(D) what the students cheated
12. Scientists believe ____ made the moon as cold as it is.
(A) that an atmosphere is absent
(B) that the absence of an atmosphere
(C) what was the absence an atmosphere
(D) an atmosphere is absent
13. ____ is decided by the ecological role that it plays.
(A) An animal sees well
(B) Whether an animal sees well
(C) Does an animal see well
(D) So an animal sees well
14. Analysts agree ____ is too much "hot money" circulating in the stock market.
(A) what
(B) which
(C) that
(D) that there
15.Have you wondered whether ____ too late to change your job?
(A) it is
(B) is it
(C) that it is
(D) is
16. ____ is impossible to tell now.
(A) When will it snow
(B) Whether will snow
(C) When it snows
(D) Whether it will snow
17. Such an opportunity, ____ , comes only once in a lifetime.
(A) the salesman says
(B) that the salesman says
(C) which says the salesman
(D) what the salesman says
18. Many voters are concerned ____ may not be able to deliver on his promises.
(A) over the candidate
(B) with the candidate
(C) that the candidate
(D) the candidate that
19. I find ____ that he didn't take the money.
(A) to believe hard
(B) it to believe hard
(C) it hardly to believe
(D) it hard to believe
20. Babylon is ____ Bagdad.
(A) that is now
(B) what now
(C) what is now
(D) that now