We must do everything we can ________ waste water from running into rivers．

keep

kept

to keep

keeping

The sign with the words “________” is often found in a hospital or a library．

KEEP QUIET

NO PHOTOS

NO PARKING

STOP

He worked very hard．________ he got good grades in the final examination last year．

By the way

On the way

In this way

All the way

I'm not the ________ of the cat．It could be Jim's．

owner

teacher

driver

inventor

I can't send an e-mail．Would you please show me ________?

what to do it

where to do

when to do

how to do it

－Do you know ________ the Olympics are held?

－Every four years．

how soon

how long

how often

how far

－When you have difficulty in English learning, you can ________ Mrs Brown for help．

－Ok, I will．

turn off

turn up

turn over

turn to

－Where is Mrs．Wilson?

－I saw her in the library ________．I'm not sure if she is still there．

right now

just now

at once

so far

－Linda, help ________ to some fruit．

－Thank you．

you

yours

yourself

yourselves

The first thing ________ we should do is to protect the wild animals．

that

which

what

how