什么情况下连接词后面直接接被动或ing形式?例句：quailstypicallyhaveshortroundedwingsthatenablethemtospringintofullflightinstantlywhendisturbedintheirhidingplaces.中的“whendisturbed”为什么不是"whenth

Question

什么情况下连接词后面直接接被动或ing形式?
例句：quails typically have short rounded wings that enable them to spring into full flight instantly when disturbed in their hiding places.中的“when disturbed”为什么不是"when they are disturbed" 因为从句的主语和主句主语一致所以省略么?

Answer 1

前面已经有了主语quails,后面为了不重复就不再写主语quails,但是像when这样的词后面不能加be-,所以直接就用了被动语态
至于你说为什么不用they are disturbed,语法上应该没错,但是这不符合英语用语习惯,本来就很长的句子应该写的简洁一点,不信你把they are disturbed带进句子里再读一遍是不是很拗口,不够简洁有力.