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

he said that they will be ok he said that they _____(NEED)more teachers here. He said that they _____at eight last night.（do） he said that they were tourists that they were tourists划线提问 一道选择题：________ been abroad before________ been abroad before. A it is said that he has B they said that he has C he is said that he hasD he is said to have怎么做? he said that they must work hard.这里后面的that代表什么? he said that they would build a bridge. 中间为什么用that链接 将下列句子变成间接引语1.Tom said,I'm watchingTVTom said that ________2.He said,I've lost my bike He said that ___________ 把下列句改为直接引语1、She said that he could go there again that night,''2、They said that they liked diong sports.'' they said that they r---- the committee. He said that they must work hard.为什么这句话用了过去式? They ___ him that he .(A.told B.said C.spoke) ——to have been rich A.they say b.he is said c.it is said d.that was said He said that __ rain they couldn't go A in caseB in case of C in that caseD if He said that that 'that' that that man used was he said they -----(call)the police everything( )they said 填what 还是 that he said that he was working hard at EnglishHe said,I'm working hard at English now.He said that he was working hard at English()直接引语与间接引语转换,快