The word "disaster" is closest in meaning to which of following?
(A) control
(B) catastrophe
(C) avoidance
(D) history
217. Helium nuclei have also been found to be constituents of cosmic rays that fall on the earth (cosmic "rays" are not really a form of radiation; they consist of rapidly moving particles of numerous different kinds) .
The word "constituents" is closest in meaning to which of following?
(A) relatives
(B) causes
(C) components
(D) targets
218. Its relative abundance never seems to varymuch. In some places, there may be slightly more of it; in others, slightly less, but the ratio of helium to hydrogen nucleial ways remains about the same.
The word "vary" is closest in meaning to which of following?
(A) mean
(B) stretch
(C) change
(D) include
219. However, the amount of helium that could have been produced in this manner can be calculated, and it turns out to be no more than a few percent.
The word "calculated" is closest in meaning to which of following?
(A) ignored
(B) converted
(C) increased
(D) determined
220. By the time the universe was a few minutes old, helium production has effectively ceased.
The word "ceased" is closest in meaning to which of following?
(A) extended
(B) performed
(C) taken hold
(D) stopped
