问题描述： sign up ,sign 1个回答 分类：综合 2014-10-29 问题解答： 我来补答 sign up sign up[简明英汉词典]跟…签订合同sign up vbto enlist or cause to enlist,as for military servicesign in sign in[简明英汉词典]通过签字(使)取得入场权sign in 签到,签收【计】 注册【计】登录sign in vbto sign or cause to sign a register,as at a hotel,club,etc 展开全文阅读
