With only 5 percent of the world's population,United States citizens consume 28 percent of its nonrenewable resources, drive more than one-third 0f its automobiles, and use 21 times more water per capita than Europeans do.
With only 5 percent of the world's population, United States citizens consume 28 percent of its nonrenewable resources, drive more than one-third of its automobiles, and use 21 times more water per capita than Europeans do.
上回说是副词说错了,应该是介词(或者是连词):一般语法书里好像都没有特别指出是什么词。 Wikipedia上是这样说的: Some subordinating conjunctions (although, before, until, while), when used to introduce a phrase instead of a full clause, become prepositions with identical meanings. 所以,though doing xxx = though he does xxx; while doing xxx = while he does xxx; before doing xxx = before he does xxx, ...这在GMAT里都是很常见的,记下来这种结构就行。