cry的三单形式是cries，单词详解：cries：哭；喊叫（cry的第三人称单数）；名词：叫喊；传闻（cry的复数）。
相关短语：Everybody cries：每个人哭泣；每个人都会哭泣；人人哭泣。
三单形式是指句子中主语为单数第三人称（如she，he，it等代词或pen这样的名词）时，谓语动词要改变形式，一般在词后加s。
解释：海底捞月，想入非非。
例句：He was a mere child in the world,but he didn''t cry for the moon.他在这世上只不过是一个小孩子罢了，可是，他想入非非。
He asked his dad to buy him a yatch as a birthday present.I think he was asking for the moon.他要他爸爸给他买一艘游艇作为生日礼物，我想他真是异想天开了。
If you want a Ph.D like that,you might as well cry for the moon.如果你这样就想拿到博士学位，那简直是异想天开。
We shouldn''t cry for the moon.不能要求不可能得到的东西。
If you want a knighthood,you might as well cry for the moon.你若想获得爵士头衔，简直形同海底捞月。