There are a lot of computers in the lab,and they need professional __________ to make sure they can be in a good state.

There would be not a good harvest of wheatin North China this year _______ the big snow.

What can you see in the picture — I can see a farm. Andthere _______ a lot of animals on it.

_______is the old bridge over the river- Not very wide. It’s about three meters.

Would you like me to help you with the homework—______________ . But I can manage it myself.