Question

Many of the earth’s plants and animals have already ______ and several other species are endangered．

A．died away

B．died out

C．died down

D．died of

Answer 1

B

短语辨析。  A．消失 B．灭绝 C．逐渐消失D．死于。句意：地球上的许多动物和指物已经灭绝，一些其它物种濒临灭绝。故选B。