由for since because as 引导的原因从句如何来快速做出选择

问题描述:

由for since because as 引导的原因从句如何来快速做出选择

分句+,for+分句;since从句+主句;主句+because从句,或Because从句+主句;
as从句+主句:
对why疑问句的回答用because.since指原因是不言而喻的.