This 65.5-million-year-old layer of Earth separates fossils of the Cretaceous period from those of the Tertiary period.

这个有着6550万年历史的地层分离了白垩纪的化石和第三纪的化石。

youdao

The system is also quite effective for locating fires that are smoldering beneath the top layer of earth -- a problem that occurs with wildfires thought to have been snuffed out.

该系统还能相当有效的定位土下的无焰燃烧--也就是森林大火被认为已被扑灭而产生的问题。

youdao

This sediment layer is enriched in the rare metal iridium and other elements that are relatively abundant in a meteorite but very rare in the crust of Earth.

这一沉积层富含稀有金属铱，以及其他在陨石中较丰富而在地壳中十分罕见的元素。

youdao

One of these satellites, CloudSat, has given the first glimpses of the middle layer of clouds in the Earth's atmosphere.

ECONOMIST: Climatology

Finally, in a third set of simulations, they doubled the CO2 in the atmosphere, but added a layer of sulfate aerosols to the stratosphere, which would deflect about two per cent of incoming sunlight from the earth.

NEWYORKER: The Climate Fixers

Nitrous oxide is also considered a greenhouse gas and is 310 times more dangerous to the Earth's ozone layer than carbon dioxide, said Joseph Johns, chief of the U.S. attorney's environmental crimes section.

NPR: Feds Raid 17 Calif. Businesses For Nitrous Oxide