I don't have to introduce him to you__you know the boy A until B unless C since D but
问题描述：
I don't have to introduce him to you__you know the boy A until B unless C since D but
答
选 C
since 既然
既然你知道这个男孩,我就没有必要向你介绍他了.为什么不选A until 翻译成直到我介绍这个男孩给你你才认识他until 和not 构成 not ……until ，意思是：直到……才如果选 until ，句子意思就成了：直到你认识了这个男孩我才有必要向你介绍他。显然不通顺。 如果要表达“直到我介绍这个男孩给你你才认识他”，英语句子应该是：You didn't know the boy until I introduced him to you.not ……until是要先翻译从句是吗是的。