When you are planting trees, the trees ________ straight in the hole.
| A．must put | B．must be put | C．are putting | D．is put |
_____ have you been swimming? For five years.
| A．How many times | B．How long | C．How often | D．How much |
It’s really cold today, ______ ?
| A．does it | B．doesn’t it | C．isn’t it | D．is it |
---He’s never been to an aquarium.
---_______.
| A．Neither have I | B．Neither do I | C．I never too | D．I don’t too |
Would you mind ______ those old jeans?
| A．don’t wear | B．not to wear | C．aren’t wearing | D．not wearing |
I have been skating _______ nine o’clock.