John knocked at the door for nearly five minutes ____his wife opened it. A before B until 选的是A

问题描述:

John knocked at the door for nearly five minutes ____his wife opened it. A before B until 选的是A
John knocked at the door for nearly five minutes ____his wife opened it.
A before B until
选的是A,为什么B不对?

before 表示在某一时间段之前,此句中有for nearly five minutes这一时间段,因此用before 更贴切
untill 一般常用于否定句中,而且表示之前一直在做(没有停),如果用在此句表示他连续不停地敲了5分钟,显然不合常理