He didn’t understand the question so there was a expression on his face.A. puzzling; pu

问题补充：

He didn’t understand the question, so there was a expression on his face.

A. puzzling; puzzled

B. puzzling; puzzling

C. puzzled; puzzled

D. puzzled; puzzling

答案：

(答案→)A. puzzling; puzzled

B. puzzling; puzzling

C. puzzled; puzzled

D. puzzled; puzzling

解析：前空令人困惑的问题；后空困惑的表情。