—Can I pay the bill by check?—Sorry，sir．But it's the management rules of our hotel that payment     be made in cash．

You _______ have told her the bad news last night, because she wouldn’t handle it peacefully.

–Look! Someone is cutting a tree on the moon.–It _______ be true, Granny. Our teacher says there is no air there.

You       buy a gift, but you can if you want to.

 -- What will the weather be like tomorrow? -- It ______ be rainy, cloudy or sunny. Who knows?