例句與造句

1. In astrodynamics, canonical units are defined in terms of an object's reference orbit.
2. This frame of reference orbits around the center of the Earth, which introduces the fictitious forces known as the Coriolis force, centrifugal force, and gravitational force . ( All of these forces including gravity disappear in a truly inertial reference frame, which is one of free-fall .)
3. It's difficult to find reference orbit in a sentence. 用reference orbit造句挺難的