Animals like to make improvement in their ways of doing things, as men do.

7. Railway signals can be divided into home signal, starting signal, distant signal, repeating signal and shunting signal.

Recycling is one way to protect the environment; reusing is another.

What kind of animals are mentioned when Zhuangzi used animal lovers to show the art of love?

holds that language originated from people’s imitations of animal cries and other sounds heard in nature.

Birds always build fashionable nests.

Beavers build their dams and huts by instinct.

She’s a ____________（lively） child and popular with everyone.