If tap water were as dangerous as some people thin

Elephants would（)if men were allowed to shoot as many as they wished. A. die down B．die o

If a seaplane is not used as a means of transpiration on water but is capable of being use

Some species disappeared or became ______ as new forms came into being that were better ad

Young people are facing an uncertain future. As the 21st century dawned, they were promis

Some people claim that in the age of television reading books is not as important as i

People in some parts of the world often take their water for ______. They use as much wate