To estimate the expansion rate of the universe is a notoriously difficult problem because there is a lack of a single yardstick that all distances can be measured by.
A To estimate the expansion rate of the universe is a notoriously difficult problem because there is a lack of a single yardstick that all distances can be measured by
B Estimating the expansion rate of the universe is a notoriously difficult problem because there is no single yardstick by which all distances can be measured
C Because there is a lack of a single yardstick to measure all distances by, estimating the expansion rate of the universe is a notoriously difficult problem
正确答案是B,求解释AC错在哪呀?看了gmatclub还有某刷题网站上的讨论,大部分人认为AC的表达不如B简洁(a lack of a single yardstick),还有部分说介词位置有问题(不应该放句末),求问介词位置这个解释靠谱吗?也属于GMAT要考察的点吗?