—_______ will your father come back from Beijing?
—In two days.
| A．How often | B．How long |
| C．How far | D．How soon |
I found _____ necessary to save energy and protect the environment.
| A．that | B．this | C．it | D．one |
In our city, _____ middle school students want to work as a teacher in the future.
| A．thousand | B．thousand of |
| C．thousands of | D．two thousands of |
Don’t _____ today’s work for tomorrow. Today’s work must be done today.
| A．put up | B．put out |
| C．put off | D．give up |
—I have no idea what to wear for the singing contest?
—Well, the dress_____ you bought yesterday may be the best choice.
| A．what | B．whom |
| C．where | D．that |
Betty is often seen ____ the old man with his housework.
| A．help | B．to help |
| C．helped | D．helps |