open - phase operation
英
美
- open adj.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
- operation n.操作；运转；经营；行动；手术；运算；生效；（复）运筹学
- phase n.相位；方面；局面；阶段；时期vt.逐步执行
- 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。
