extinction可数吗

　　This period of extinction wasn't comprehensive.

　　这一时期的'灭绝并不彻底。

　　What could cause such high rates of extinction?

　　是什么导致了如此高的物种灭绝率？

　　One consequence of global warming is extinction.

　　全球变暖的后果之一是物种灭绝。