If we ______ take environmental problems seriously, the earth _______ worse and worse.
| A．don’t; will be | B．won’t; isn’t |
| C．won’t; is | D．don’t; won’t be |
We are playing football. Come and _____________ us.
| A．join | B．join in | C．play | D．do |
My teacher helps us _______ swimming.
| A．on | B．in | C．for | D．with |
My mother is a nurse(护士) and is good _______ kids.
| A．in | B．for | C．with | D．at |
They need two _________ for their music club.
| A．musicians | B．dancers | C．runners | D．swimmers |
He can swim very well, ______ he doesn’t want to join the club.
| A．and | B．but | C．/ | D．or |