请教几个语法问题

jessica0912

72. The number of undergraduate degrees in engineering awarded by colleges and universities in the United
States increased by more than twice from 1978 to 1985.
(A) increased by more than twice
(B) increased more than two times
(C) more than doubled
(D) was more than doubled
(E) had more than doubled
为什么不能选A阿，


Paleotologist Stephen Jay Gould has argued that many biological traits are not the products of natual selection,favored (due to their enhancement of reproduction or survival, but that they are )simply random  by-products of other evolutionary developments.
C. because they enhance reproduction or survival, but
D.because they enhance reproduction or survival, but are
答案D
not 和but不是平行的吗为什么but 后面还有are 呢？


　26 In its most recent approach， the comet Crommelin passed the Earth at about the same distance and in about the same position， some 25 degrees above the horizon， that Halley's comet will pass the next time it appears.

　　（A） that Halley's comet will pass

　　（B） that Halley's comet is to be passing

　　（C） as Halley's comet

　　（D） as will Halley's comet

　　（E） as Halley's comet will do
为什么E不对呢，我觉得DE都对啊

stbird

有BY，和increase不是合理搭配
不知道是不是应该选B，对于double的用法我一直很糊涂

stbird

加do的话，估计用og的话来说就是WORDY了，而且把do和it appears放那么近，恐怕也是会有歧义和模糊不清的吧