He drove slowly on the way home until he reached the highway the speed limit was 60 mile

问题补充：

He drove slowly on the way home until he reached the highway, the speed limit was 60 miles per hour.

A. because

B. which

C. where

D. that

答案：

A. because

B. which

(答案→)C. where

D. that

解析：先行词是highway表示地点，定语从句中不缺主语和标语，故用关系副词在从句中作地点状语。

【标签】定语从句关系副词