难度：****

Found between about nine and 19 miles above Earth's surface, the ozone layer is a broad region of the stratosphere where the molecule, which contains three oxygen atoms, is particularly concentrated.

found between about....是过去分词短语，作为ozone layer的定语。这种定语前置少见。

在9~19英里高的地球表面发现一个范围广大的区域型臭氧平流层，里面的分子是3个氧原子构成，尤其是在这里发生浓缩。

The agreement has garnered global signatories, several rounds of successful amendments and the near-total elimination of the chemicals that break down ozone.

garner 有收获，收集的意思，这里它有三个宾语：signatories， amendment和elimination；

break down 破坏的意思 elimination 消除

协议已经获得全球各国的签署，得到多轮的成功修订以及消除了几乎所有破坏臭氧层的化学物质。