这座雕像的底座是由大理石制成的。

The statue stands on a marble ___base.

这家航空公司的运营基地位于上海浦东机场。

The airline's ___base is located at Shanghai Pudong Airport.

氨水是一种弱碱，常用于清洁窗户。

Ammonia water is a weak ___base often used for cleaning windows.

这家科技公司将总部设在硅谷。

The tech company ___bases its headquarters in Silicon Valley.

诚实是所有道德的基础。

Honesty is the ___basis of all moral values.