Now there’s a system _________ the waste is disposed of using the principles of ecology.
______ to give up smoking, he threw away his ______ cigarettes.
In class, fewer of the students who are not ______ their studies sometimes ______ the dying robots, not listening attentively.
Only when you ____ what you have learned to practice _____ say you have made it.
_____ is known to us all is that the 2010 World Expo will take place in Shanghai.
You may lie ______ the ground is dry.