第17题: [单项选择]1 2 4 8 16() A. 32 B. 24 C. 64 D. 48 参考答案:A
第18题: [单项选择]We were told that we should follow the main road ______ we reached the central railway station. A. whenever B. until C. while D. wherever 参考答案:B 答案解析:[考点] 连词 [解析] until/till…“直到……为止”,whenever无论何时,while“当……的时候,虽然”,wherever“无论哪里”,故正确答案为B。主句用肯定形式,谓