"He said that they must work hard."为什么这句话用了过去式?

"He said that they must work hard."为什么这句话用了过去式? he said that they must work hard.这里后面的that代表什么? he said i was hard-working 为什么这句话中有两个过去式? They must work hard ,反意疑问用什么? 用括号中的词填空1.It is said that they have finished the hard work _ 英语翻译He said that he ___ ___ ___ the hard work Many student said that they would work hard to make their dr Many students said that they were willing to work hard to ma 连词成句 must,work,the,in,can,they,hard,that,workers,time,the,fi he said that they would build a bridge. 中间为什么用that链接 He was so hard working that in his life time请问这句话为什么加that? it is said that后面用过去式么,It is said that he always play soccer