作者：英吉
Scientists have found signs that moving water changed the chemical makeup of the surface of Mars in recent eras, therefore concluding that its crust is harboring up to three times as much water than was previously thought.
(A) eras, therefore concluding that its crust is harboring up to three times as much water than was
(B) eras, therefore concluding that the planet's crust harbors up to three times as much water or more as was
(C) eras and have therefore concluded that the planet's crust harbors up to three times as much water as
(D) eras and they have concluded, therefore, that its crust harbors up to three times as much water, or more, than
(E) eras and concluded, therefore, that the planet's crust is harboring up to three times more water as was
原文意思：科学家发现水改变了火星表面的构成，因此得出结论火星地壳正在怎么样
题目分析：A用its crust，有的选项用planet's crust，显然后者更准确，A和D干掉。B读到three times as much water or more as was，很别扭，more是更的意思，而as是和。。一样的意思，两者放在一起意思矛盾，干掉。C用and have和前面形成一个并列，而且后面用as。。as读起来通顺，留着。E又把more和as放在一起，意思矛盾，杀！
