n.化石化；固定化；陳腐

He found a piece of fossil of an ancient bird. 他發(fā)現(xiàn)一塊古代鳥類的化石。

This fossil may be over 2 million years old. 這化石可能超過二百萬年了。

Can you date the fossil exactly? 你能確定這化石的確切年代嗎?

Isn't Professor Bell an old fossil? 貝爾教授真是個老頑固。

A microscopic fossil, as of a pollen grain or unicellular organism. 微體化石一種微小的化石，如花粉粒或單細(xì)胞有機(jī)體的化石

If we squander our fossil fuels, we threaten civilization. 如果我們浪費(fèi)礦物燃料，我們就威脅文明。