常见例句They are the first cirrus clouds seen on an outer planet.它们是首次在外行星上发现的卷云。The planet is twice as large as the earth and is the smallest exoplanet ever found.这颗行星的体积是地球的两倍，是到目前为止天文学家发现的体积最小的太阳系外行星。 返回 superior planet