请给分析一下这段英语中两个句子的时间关系,和因果关系.
2个回答

She wrote that her husband,because of a business,could not leave until July.This was because he had to be in London again within a month.

她信中写道,她的丈夫因工作关系,七月之前都不能离开.因为他在一个月内必须再到伦敦一次.

后面一句是因,前面一句是国,this is because 中的this就指的是前一句话