field shifting造句

• Some 35 years on , reflectors placed on the lunar surface are still used by scientists interested in geophysics and geodesy ( for example , how the moon ' s gravitational field shifts over time )
  35年来，放置在月球表面的反射镜依然在使用，一些对地球物理学和测地学感兴趣的科学家用它们来研究月球的引力场如何随时间变化。