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

Some animals______well enough in that country.A．have not protectedB．is not being protected

A．Many species have developed a habit of migration.B．Many species have become less sen

Ecologists have studied the four chipmunk species that occur on the eastern slope of the S

The following are endangered species EXCEPTA．tigers.B．whales.C．polar bears.D．some types of

Among almost seven hundred species of bamboo, some are fully grown at less than a foot hig

It could be argued that human beings are a species of animal. However, the unique charact