Every youngster should be encouraged to know his own potentialities and to weigh the chanc

Fuel injection valves should be taken out, cleaned, and lifting checked every _____.

We should enable every student _________morally, intellectually and physically.A: de

How often should the lubricating oil of a diesel engine be changed？A.After every tripB.Eve

Every nation should treasure its cultural（), as it demonstrates the growing－up history

A（An)______ should be issued for every company complying with the requirement of the ISM C

Woman: Protecting the environment should be on the agenda of every one of us. Man: You too