A stubborn boy like him dosen’t learn from his mistakes he was punished badly.A. ifB. when

问题补充：

A stubborn boy like him dosen’t learn from his mistakes he was punished badly.

A. if

B. when

C. since

D. unless

答案：

A. if

B. when

C. since

(答案→)D. unless

解析： 考查连词，if 如果， when 当什么时候，since 自从，unless 除非，句意：像他这么笨的男孩根本不会从错误中学习除非除非他受过严重的惩罚。所以选D。