Please （ ） the water tap when you have finished your washing．

The purpose of the conference is to （ ） the friendship among the Asian countries.

_____ more time， he’ll make a first-class tennis player sooner or later.

（ ） is known to all, the earth moves around the sun once a year.

The reason is （ ） he is unable to operate the machine.

（ ） relatively costly, the engine is highly efficient and needs servicing infrequently.

He had his book ______ at his own expense.

The chemical factory was pulled down _____protecting the environment.

Ten minutes _____ an hour when one is expecting a phone call.

We arranged to meet at the station but she did not （ ）.

Proper_____can ease people’s relationship and make their conversation more pleasant.

The two companies decided to （ ） on a project concerning animal cloning.