The problem referred to at the meeting, if___________in time , will have a bad effect on the environment.

Effective measures have been taken to prevent _______pollution.

Who will teach _____ Chinese next term Can it be a new teacher–Perhaps. But our head teacher hasn’t told us ____ .

The parking meters are installed in streets to record and show the time _____ a driver has paid for is finished

Technology has quickened the rate _________ wecommunicate with the world around us