We were told that we should follow the main road ________ we reached the central railway station．

We were told that we should follow the main road ________ we reached the central railway station．

A.whenever

B.until

C.while

D.wherever

答案及解析： B

解析：

根据follow的含义可知后面的空格处应该是能和表示延续动词搭配的连词，而whenever“无论何时”，while“当什么时候”，wherever“无论何地”，都不合题意，故选择B项。