normal undertaking

• 平常的事情

normal undertaking的用法和样例：

例句

1. The cosmological redshift is not a normal Doppler shift.
   宇宙学的红移并不是平常的都卜勒偏移。
2. When two Americans meet for the first time-it is normal for them to call each other by their given names immediately.
   两个美国人初次见面，很快就直呼其名是很平常的事。