The walls are made of concrete three feet thick and the doors weigh more than 300,000 pounds.

墙壁由3英尺厚的混凝土制成，门重量超过30万磅。

All across this area massive eruptions happened that laid down lava 2,000 feet thick in some places and that cooled into this.

整个地区都发生了大规模的喷发，在一些地方形成了 2000 英尺厚的熔岩，然后冷却成这样。

With his troops at the ready and walls 20 feet thick, King Henry slept soundly on the top floor.

凭借他的军队和 20 英尺厚的墙壁，亨利国王在顶层睡得很香。

If carbon dioxide is a blanket of average thickness over heating the earth for centuries, methane is like a blanket seven feet thick with over 80 times the heat-trapping power of CO2 for about two decades after its release.

如果二氧化碳是覆盖在地球上加热的毯子，已经持续几个世纪，那么甲烷就像是一条七英尺厚的毯子，在释放后的大约20年内，它捕捉的热量是二氧化碳的80多倍。