大全987-199（有关of sth'sth）

Car owners who inflate their tires properly can substantially boost their vehicles' fuel eficiency, since the increace in car-road friction can waste up to five persent of car fuel by underinflation.

A

B  Becuse the underinflation of tires can watst up to five persent of a car's fuel by increasing car-road friction, car owners can substantially boost their vehicles' fuel efficiency by properly inflating the tires

C Their vehicles' fuel efficiency is substantially boosted by car onwers through the proper inflation of tires that, when underinflated, can waste up to five persent of car fuel by an increase in car-road friction.

D The proper inflation of tires by car owners, due to the fact that underinflation can waste up to five persent of a car's fuel by the increase of car-road friction, can substantially boost their fuel efficiency.

E Because up to five persent of a car's fuel are wasted throung the increases in car-road friction when the tires are underinflated, car owners properly inflating tires can substantially boost their fuel efficiency

答案是B， 我选了A， 理由是排除了所有 a of b’的结构的选项。看到答案后在仔细看看A，发现问题可能出现在who inflate their tires的their应该是指cars（若指car owners tires会不会很奇怪？） 

究竟A OF B’结构在GMAT考试里面算不算错的？~ 

C 结构不好,舍弃.

E 和 D THEIR 有歧义.

A 与 B 由因果关系的逻辑性来讲,B比A 好.