At the current rate of decline, many of the rain forest animals could become extinct in less than 10 years.

按照目前的下降速度，许多雨林动物不到十年就会绝种。

We must protect these endangered animals before they become extinct.

在这些濒危动物灭绝之前，我们必须保护它们。

Why did Neanderthals become extinct?

为什么尼安得塔人会灭绝呢？

"We're going to become extinct," he said.

“我们将要灭绝，”他说。

"Homo sapiens will become extinct, perhaps within 100 years," he said.

“智人可能会在100年内灭绝，”他说。