How much did you pay _________ the dictionary?

A．of　　B．to　　C．for D．on

The boys have been skating _____ three hours．

A．in B．for C．since D．before

She bought _________ umbrella yesterday．

A．a　　B．an　　C．the D．／

Don’t put off ________ the room．

A．clean

B．cleaning

C．to clean

D．cleaned

My father has been a teacher ________．

A．since 20 years　　

B．for 20 years ago

C．since 20 years ago

D．from l985

She needs __________ the flowers every day．

A．water

B．watered　　

C．to water

D．watering

Does Mary often help her mother ________ housework?

A．do B．does C．doing D．did

I'd like __________ the football match．

A．watch　　

B．to watch　　

C．watching

D．watched

A snake robot could look for people _______ under a building.

A. trapping

B. trap

C. trapped

D. traped

I’ll be back home _______ two hours.

A. for　　B. at　　 C. over　　 D. in