proto-planetary disk

• 原行星盘

proto-planetary disk的用法和样例：

例句

1. These clouds, known as protoplanetary disks, are the stuff from which planets are formed, and without them no planetary system can evolve.
   这些云就是原行星盘，行星诞生的材料来源，没有它们行星系统就不能演化。