Some people have become concerned _____ another kind of pollution.A、aboutB、withC、forD、by

The quality of many people’s lives has become worse in some ____ because of technological progress.

According to the passage people who have experienced ups and downs may become______.A．nerv

Some species of animals have become extinct because they could not ______ to the environme

Ensuring an adequate water supply have been a concern ever since people began to live in t

Mobile phone has become a problem for middle schools. Some middle schools in Australia have banned s

Some people tend to have better memories than the