The ocean seems invulnerable because it is vast and under-explored.
海洋看似坚不可摧因为它广博而且未经充分开发。
2
The Qinghai-Tibet Plateau is located in the east part of the Tethys realm that is the largest petroliferous region onshore in China which is under-explored.
位于全球特提斯巨型油气构造域东段的青藏高原是我国现今陆上面积最大、油气调查和研究程度最低的地区。
3
They explored the gradations between "cyclical" and "structural" unemployment, and the conditions under which one or the other arises or gives way to the other.