Oort cloud
例子
The Oort Cloud is a theorized reservoir of comets and icy bodies that extends far beyond the solar system.
奥尔特云是一个理论上的彗星和冰体储存库,延伸到太阳系以外很远的地方。
The Oort Cloud is considered a source of long-period comets that occasionally enter the inner solar system.
奥尔特云被认为是偶尔进入内太阳系的长周期彗星的来源。



























