earth lead

例句：

1. 1. The geologists are trying to understand the earth's crust.
   地质学家正在试图理解地壳。
2. 2. The earthquake caused a large landslide in the earth's crust.
   地震导致地壳发生了一次大规模的滑坡。
3. 3. The scientists believe that the earth's crust is constantly changing.
   科学家们认为地壳一直在不断变化。