环形的

Lunar craters can be plainly seen with the aid of a small telescope.

借助小型望远镜可以看清月球上山。

The chairs have soft seat, stylized cabriole legs and interlocking hoops in the back for a more formal look.

这款餐椅有柔软坐垫，优雅弯曲凳腿以及靠背上图案，是美式餐椅经典款式。

An annular cavity placed around the anode of arcjet was designed to form a regenerative cooling channel on the base of an arc jet.

该文在原有电弧加发动机基础上进行改进，设计了覆盖发动机阳极空腔，成再生冷却通道。

There is a space between a peribacteroid membrane and a bacteroid cell wall, the size of spaces is variable in different bacteroids or the different parts of a bacteroid.

在细菌周膜与细菌细胞壁之间有腔隙，腔大小随细菌和细菌部位不同而异。