.
—Who______ it be that is knocking at the door?
—It ______ be Father, but I’m not sure.
| A．can; must | B．can; may | C．must; can | D．may; must |
He just stared at me and there was an expression in his eyes that I couldn’t．
| A．tell | B．watch | C．read | D．feel |
When I got off the crowded bus, I found my pocket _____ and the disk in it with the important documents gone.
| A．picked | B．stolen | C．missing | D．lost |
We can never expect ____ bluer sky unless we create _____ less polluted world.
| A．a; a | B．a; the | C．the; a | D．the; the |
The newly discovered star was named ___a Chinese astronomer ____ honor of his contributions to astronomy.
| A．for; in | B．after; for | C．as; in | D．after; in |
-----Good morning, Xueyuan Hotel．
-----Hello, I’d like to book a room for the nights of the 14th and 15th.
-----_______.
| A．No problem. | B．Just a minute, please. |
| C．What can I do for you? | D．What’s the matter? |