must過去式和過去分詞

must例句

1、We must make good use of the available space.

我們必須充分利用現有空間。

2、And again, we must think of the cost.

再說，我們必須考慮成本。

3、You've been a great help, I must say.

依我看，你真是幫了個大忙啊。