The ocean bottom is made up of smooth plains.

洋底 由平坦的平原构成。

What do you think the ocean bottom is made up of?

你认为海底是由什么组成的？

Most of the ocean bottom is made up of smooth plains.

海底大部分是由平坦的平原构成。

Many high-gain stations will be deployed on land and ocean bottom.

在陆地和洋底要设置许多高增益的台站。

A method for second positioning of ocean bottom cable is demonstrated.

文章提出了海底电缆二次定位的一种新方法。