you have (got) to be kidding
informal also you must be kidding used to show that you are very surprised by what someone has said and do not accept it:
You want me to drive into the city? You’ve got to be kidding.
英语词典包含110679条英英释义在线翻译词条,基本涵盖了全部常用单词的英英翻译及用法,是英语学习的有利工具。