The external source may be a database.

外部源可能是数据库。

Insects need an external source of sterols.

昆虫需要外界来源的固醇类。

Awaiting inFORMation from external source. Please be patient.

等待他方提供信息。请耐心等待。

Radio galaxy is also a strong red external source and X-ray source.

射电星系同时也是强的红外源和X射线源。

When forward motion is imparted to it from an external source, air is forced.

当由外部能源强迫其向前运动时，空气被迫进入进气道。