For geophysical purposes it is customary to use solar rotations of 27. 0 day . 为适应地球物理学的需要，习惯上以270日为太阳自转周期。
2.
For geophysical purposes it is customary to use solar rotations of 27 . 0 day 为适应地球物理学的需要，习惯上以27 0日为太阳自转周期。
3.
The rotation of the original gas and dust cloud becomes the revolutions of the planets around the sun and the rotation of the sun itself 气体尘埃云原先的转动，成了行星公转和太阳自转的原动力。整个过程大约用了
