Last month 3 people got injured in a gas explosion, has not been discovered yet.
A. whose cause
B. the cause of that
C. which cause
D. the cause
网友回答
(答案→)A. whose cause
B. the cause of that
C. which cause
D. the cause
解析：上个月3个人在煤气爆炸中受伤，爆炸的起因还没有发现。先行词是a gas explosion，定语从句中cause缺少定语，用whose引导定语从句，或the cause of which，选A。