许多科学家认为恐龙在6500万年前就已经灭绝了。

Many scientists believe dinosaurs became ___extinct about 65 million years ago.

这座火山已经休眠数千年，被认为是死火山。

The volcano has been dormant for thousands of years and is considered ___extinct.

这种古老的制陶技艺现在已经失传了。

The ancient pottery-making technique is now ___extinct.