没事就做吃货
arm单复数都可以用,至于何时用单数,何时用复数,要根据具体语境判断。以下分别是柯林斯词典和牛津词典的例句:He had her by the arm and he was screaming at her.他抓住她的胳膊,冲着她大喊。He waved his arms expansively.他豪爽地挥舞着双臂。第一个句子arm用单数,因为根据日常经验判断,我们平常抓人胳膊往往都只抓一只胳膊。而第二句想要表达“挥舞双臂”的意思,那么这时候如果单数,挥着的就是只是一只胳膊而不是“双臂”了。