星云的英文：
nebula

The element hydrogen comprises 90% of the matter in gaseous nebulae
元素氢占气体星云物质的90%。

galactic nebulas are masses of diffuse material within our galaxy
银河星云是我们星系中的一团团弥散物。

For the Galaxy and the andromeda nubula, they do not form a pair of galaxies completely isolated from all others
对银河系和仙女座星云来说，它们并不构成与所有其他星系完全孤立的一对星系。

These sources are generally viewed in projection against radio nebulae representing the remnants of supernova outbursts
这类源一般都投影在超星爆发残骸的射电星云上。

The spiral nebulae are impressive objects.
旋涡星云是迷人的天体。

The spiral nebulae are impressive objects
旋涡星云是迷人的天体。

You can see nebulae in the clear summer sky
在晴朗的夏夜可以看到天上的星云。

The element hydrogen comprises 90% of the matter in gaseous nebulae.
元素氢占气体星云物质的90%。

The remnant nebular gas pervades the interplanetary space
星云的残余气体充斥星际空间。

Good spectra of the spiral nebulas are difficult to obtain because of their extreme faintness
旋涡星云因为非常暗，难以得到它们的清晰的光谱。

The spiral nebulae are impressive objects.
旋涡星云是迷人的天体。

The element hydrogen comprises 90% of the matter in gaseous nebulae
元素氢占气体星云物质的90%。

The element hydrogen comprises 90% of the matter in gaseous nebulae.
元素氢占气体星云物质的90%。

galactic nebulas are masses of diffuse material within our galaxy
银河星云是我们星系中的一团团弥散物。

Good spectra of the spiral nebulas are difficult to obtain because of their extreme faintness
旋涡星云因为非常暗，难以得到它们的清晰的光谱。