分类：教育/科学-学习帮助
问题：aquestionItwasevening_____wereac 
It was evening_____we reach the little town   of Winchester.A that  B until  C since  D  beforethe answer is D not Bwhy can't we choose B here?
回答：It was not ....unitl是固定用法"直到.....才"句中缺少not,而before这里是解释为"在我们到达以前这里就是晚上了"