托福阅读历年真题精选2_第2页

12. The word "heart" in line 4 is closest in meaning to

(A) center

(B) edge

(C) tail

(D) beginning

13. Why does the author mention the Giotto probe in paragraph 3?

(A) It had a relatively small and inconspicuous nucleus.

(B) It was very similar to an asteroid.

(C) It was covered with an unusual black dust.

(D) It provided visual evidence of the makeup of a comet's nucleus.

14. It can be inferred from the passage that the nucleus of a comet is made up of

(A) dust and gas

(B) ice and dust

(C) hydrogen gas

(D) electrically charged atoms

15. The word "graphic" in line 9 is closest in meaning to

(A) mathematical

(B) popular

(C) unusual

(D) vivid

16. Which of the following occurred as the ices from Halley's Comet evaporated?

(A) Black dust was left on the comet's surface.

(B) The nucleus of the comet expanded.

(C) The tail of the comet straightened out.

(D) Jets of gas caused the comet to increase its speed.

17. All of the following statements about the tails of comets are true EXCEPT:

(A) They can contain electrically charged or neutral particles.

(B) They can be formed only when there is sufficient heat.

(C) They are formed before the coma expands.

(D) They always point in the direction away from the Sun.

18. The word "distinct" in line 17 is closest in meaning to

(A) visible

(B) gaseous

(C) separate

(D) new

19. Compared to the tail of electrically charged atoms, the tail of neutral dust particles is

relatively

(A) long

(B) curved

(C) unpredictable

(D) bright