--- Look! It ____ be Jack on the playground.
---It ____ be him. Because I saw him enter the school library just now.
A. may; mustn’t B. must; can’t C. can; can’t
I don’t know _________, but I guess he may be a doctor.
| A．what is he | B．how he does |
| C．what he is | D．what does he do |
— I wonder ________ you water this kind of flower.
---Every other day.
| A．how often | B．how long |
| C．how soon | D．how much |
Try on this red skirt; you will look great ________it.
| A．on | B．by | C．in | D．for |
—Will someone go and get Dr White?
—He’s already been _________.
| A．asked for | B．sent for | C．called off | D．looked for |
My parents have promised to come to see me before Ifor Africa.
| A．have left | B．leave | C．left | D．will leave |