20. The passage suggests which of thefollowing
about the “force” mentioned in lines 16 and
18?
(A) It is responsible for most of the major
geologic events that have occurred.
(B) It is responsible for most of the marine
extinctionsthat have occurred.
(C) Its recurrence is unlikely to be able to be
predictedby scientists.
(D) Its existence was not seriously considered
byscientists before Raup and Sepkoski did
theirresearch.
(E)Its existence was confirmed by the research
ofRaup and Sepkoski.