useful surface的意思|示意

At one point in the documentary, Hawking describes how feet would be useful for any life form that has evolved on a solid surface.

记录片中，霍金曾一度讲到对于在固体表面进化的任何生命形态而言，脚都是极其重要的。

Making up around 5.6 per cent of the surface material, it was present in sufficient quantities to be useful to future manned missions.

在月球表面，水约占总物质含量的5.6%，这些储存量足够保障人类未来在月进行的各种探索任务。

This article gives you a variety of examples of useful queries, but we have only scratched the surface.

本文提供了各种有用的查询示例，但我们只是略微涉及一点皮毛而已。