气体既无一定体积，又无一定形状。

A gas has neither definite volume nor definite shape.

youdao

总之，气体既没有一定大小，又没有一定形状。

In one word, a gas has neither definite size nor shape.

youdao

这种海绵铁可以锻成一定形状，用来制造工具和武器。

This spongy iron could be hammered into shape to make tools and weapons.

youdao

From this point of view, they have a certain shape, size and so forth.

从这个视角看，他们有一定的形状大小等等。

斯坦福公开课 - 7个颠覆你思想的演讲课程节选