Which floor is your classroom ____________ that classroom building?
| A．on | B．in | C．on; in | D．in; on |
There is _____pollution and ____fishes in the river now than 20 years ago.
| A．more, less | B．more, fewer | C．less, much | D．fewer, many |
The sign（标志牌）made us safe.
| A．feel | B．feels | C．to feel | D．felt |
Everyone should play a part in _____the earth.
| A．save | B．saves | C．saving | D．saved |
-- ________ will Mr. Green be back? -- In a week, I think.
| A．How often | B．How many | C．How long | D．How soon |
It's easy ______ a banana milk shake. Let me help you.
| A．do | B．to do | C．make | D．to make |