21. Experiments in the sonic imaging of moving objects …………… in both the

United States and Europe well before the Second World War.

A. were conducting

B. have been conducted

C. had been conducted

D. being conducted

>>>C

22. …………… billions and billions of stars exist in the vast space beyond our Milky

Way galaxy.

A. That is estimated

B. An estimate that

C. That the estimate

D. It is estimated that

>>>D

23. …………… gene-bearing bodies within the nuclei of living organisms.

A. Chromosomes

B. Chromosomes that are

C. Chromosomes are

D. Chromosomes while they are

>>>C

24. Abner Doubleday, ……………, was credited with the invention of baseball in

1839.

A. who become a Union army general

B. which became a Union army general

C. who were a Union army general

D. a Union army general

>>>D

25. …………… photosynthesis were to stop, life would disappear from the planet

Earth relatively quickly.

A. For

B. However

C. If

D. Although

>>>C

26. Each fiber in the bundle …………….. only a tiny fraction of the total image.

A. transmit

B. transmitted

C. transmits

D. to transmit

>>>C

27. Antonio Gaudi, architect of Barcelona's Holy Family Church, died before seeing …………… the structure.

A. on completion of

B. the completion of

C. completing of

D. their completing of

>>>B

28. This is the factory …………… at work.

A. they are

B. where they are

C. where are

D. in where they are

>>>B

29. America's first globe maker was James Wilson, who …………… and blacksmith in his earlier life.

A. a farmer had been

B. had been a farmer

C. farming

D. being a farmer

>>>B

30. Napoleon …………… the West Indian island of Santo Domingo in 1801.

A. attacked

B. is attacking

C. has attracted

D. attacking

>>>A

31. Modern industrial methods have supplanted individual crafts, …………… stone carvers, coopers, and cobblers virtually extinct.

A. make blacksmiths,

B. made blacksmiths,

C. making them blacksmiths,

D. making blacksmiths,

>>>D

32. Not only knowledge and skills, but also attitudes …………… in school for students' future adjustment to society.

A. when cultivated

B. cultivated

C. which need to be cultivated

D. need to be cultivated

>>>D

33. On Mercator's maps, the far northern and southern polar regions are

……………

A. greatly exaggerated in area.

B. exaggerating greatly in area.

C. greatly exaggerate in area.

D. great exaggeration in area.

>>>A

34. On the slope of Long's Peak in Colorado …………… the ruin of a gigantic tree.

A. that lies

B. lies

C. where lies

D. lie

>>>B

35. …………… in Shanghai than in any other city in China.

A. More people live

B. More people living

C. It has more people

D. More living people

>>>A

36. The earth spins on its axis and …………… 23 hours, 56 minutes and 4.09

seconds for one complete rotation.

A. need

B. needed

C. needing

D. needs

>>>D

37. …………… on the environment for the gratification of its needs.

A. Each organism to depend

B. Every organism depends

C. All organisms depending

D. Many organisms can depend

>>>B

38. Of Charles Dickens' many novels, expectations perhaps …………… to many readers.

A. the most satisfying one

B. most satisfying one

C. more than satisfying one

D. the more satisfying than

>>>A

39. ……………, the nation's capital remained in Philadelphia, Pennsylvania.

A. While designing Washington, D.C.

B. Washington, D.C., was designed

C. While Washington, D.C., was being designed

D. Washington, D.C., designed

>>>C

40. Children learn primarily by …………… the world around them.

A. experiencing directly of

B. experience direct

C. directly physical experience

D. direct physical experience of

>>>D