例3:
a) People have been fighting against the influence of TV commercials, but it often proves useless.
b) People have been fighting against the influence of TV commercials, but the effort often proves useless.
分析:it 指什么?如指influence,则在 it often proves useless 这个句子中显然不通。写作人知道it指人们的努力,但effort 这个词前面没有出现过,就不能用it。
6. 相邻的句子,检查是否避免了不必要的结构转变
例4:
a) While we reuce the number of vehicles, the speed of traffic can be increased.
b) While the number of vehiles is reduced, the speed of traffic is increased.
注意:两个非常相关的意思,不要一个使用主动结构,一个使用被动结构。