... So (so是针对前面句子的)(we failed because...这个不存在“连用”)
错误“连用”实例:
原文:因为他病了,所以他没去上学。
译文:(误) Because he was ill, so he didn't go to school.
译文:(正) Because he was ill, he didn't go to school.
评析:在英语中,如果原因状语从句用because引导,主句就不能用so; 反之,主句用so,从句就不用because。