Hints： 只听写例句。前面的单词不用听写。
The tiny, delicate skeletons are usually scattered by scavengers or destroyed by weathering before they can be fossilized.
微小，脆弱的骨骼，常常被拾荒者或者天气毁坏，而难以成为化石。 ——译文来自: lvbufan