The clock was striking twelve down the street.
A. because I walked
B. as I walked
C. since I was walking
D. while I was walking
网友回答
A. because I walked
(答案→)B. as I walked
C. since I was walking
D. while I was walking
解析：句中的strike是非持续性动词，其动作与walk同时发生，用as不用while.