nebulae

1.Extragalactic nebula is invisible to the naked eye.

我们用肉眼是看不到河外系。

2.You can see nebulae in the clear summer sky.

在晴朗夏夜可以看到天上。

3.A bit of mould is a pleiad of flowers;a nebula is an ant-hill of stars.

一粒霉菌是一簇美不胜收花朵，一撮是无数天体蚁聚。

4.The tiny but intriguing yellowish arc visible near the blue nebulae marks young variable star R Coronae Australis.

在蓝附近，但迷人弧状可见物标出了年轻可见恒南冕座R位置。

5.As our nebula began to collapse under its own gravity and spin faster, a dense clump of matter formed in the center. It's called a protostar.

当我们在自身重力作用下崩溃和更加快速地旋转时，中心形成了密集物质块。这叫做原恒。