You’d better put a cloth over the salad to ______ the flies for the sake of health.
Li Ming is a student who is easy ___ though he has some trouble ____ his lessons.
It was in 2008 ______ a terrible earthquake hit Wenchuan, Sichuan Province.
The system has been designed to give students quick and easy ______ to the digital resources of the library.
---Have you _____ completing the work given by your boss? ---Not yet, though I have tried to.
China is a country ____the Third World, _____ means her economy still needs developing very much.