Airpollutionisgettingmoreandmo

Air pollution is getting more and more serious，so we must take action________it is too late.

A．before	B．after
C．until	D．when

登录免费查看答案和解析

相关试题

I think she is right but I am not completely sure.

A．Somewhat

B．somehow

C．somewhere

D．sometime

收藏答案/解析

The club, _ _ 25 years ago, is holding a party for past and present members.

A．founded

B．founding

C．being founded

D．to be founded

收藏答案/解析

When Peter speaks in public, he always has trouble _ the right things to say.

A．thinking of

B．to think of

C．thought of

D．think of

收藏答案/解析

As Jack left his membership card at home, he wasn't allowed
into the sports club.

A．going

B．to go

C．go

D．gone

收藏答案/解析

Bird's singing is warning to other birds _______ away.

A．to stay

B．staying

C．stayed

D．Stay

收藏答案/解析