看兩個例子,幫我總結(jié)一下must be的用法!
1.He must be home before six o'clock.
He has to be home before six o'clock.
2.He must be tired.
I think he is probably tired.
這是課后練習中的題目要求,要求模仿例句改寫以下句子：
He must be here at six o'clock.
He has to be here at six o'clock.
He must be busy.
I think he is probably busy.
句中的must be應該是“一定”的意思吧,為什么有的改寫成have to ,有的改寫成probably?