-When did he start his own business?

不是强调句,
如果用that的句子应该是-It was in 1988 （that) he graduated from his senior high school.
这里用when,是时间状语
强调句 应该用在回答和问题一致
强调句的引导词不是跟who或that吗 怎么可以跟when ?不是强调句， 是时间状语。如果用that的句子应该是-It was in 1988 （that) he graduated from his senior high school.还有一个答案 就是 that 啊 可是答案错了 。。怎么判断是时间状语从句 不是that 去掉句意不变吗强调句型：“It is（was）＋被强调的部分＋that（who）＋原句其它部分”来强调说话人的意愿.被强调的部分为“人”时用who，为“物”时用that英语的强调句有个特点，就是去掉it was 和 that 再把剩下的连起来，剩下的部分一定能够组成一个完整的句子， 如果是单选，就是去掉it was 和 that 再把剩下的连起来，如果完整，就是强调句，选that，不是，就是when去掉那不是完整的吗 怎么还不是强调句 是时间状语从句打错了，应该是强调句，我认为答案是 it was ... that ...即：It was in 1988 （that) he graduated from his senior high school.(强调句）区别：It was1988 （when) he graduated from his senior high school（ 时间状语从句）