openadj.开着的；开放的；公开的v.打开；张开；展开；摊开；开始(某事物)；开张；营业；以…开头；宣布启用n.户外；公开open water开敞水面,开阔水面,无冰水面

1. It could not have been taken from Earth because Neptune never shows a crescent phase to sunward Earth.
   我们在地球看不到海王星的位相，因为地球较靠近太阳，从地球看出去，海王星永远是全相。