它们实际上在落在地球上的陨石物质中占了接近总数。
They actually account for almost all of the meteorite material that falls to earth.
铱存在于陨石和火山物质中，但在火山物质中同时包含高浓度的镍和铬。
Iridium occurs in meteorites and volcanic material, but in the latter case it is accompanied by elevated levels of nickel and chromium.
毕竟，太阳中任何元素的原子，比如说铁，都比陨石标本的原子要多得多，但这两种物质中铁和硅的比例可能是可以比较的。
After all, the Sun has many more atoms of any element, say iron, than does a meteorite specimen, but the ratios of iron to silicon in the two kinds of matter might be comparable.
应用推荐