The question was so that there was a expression on the teacher's face.A. puzzled; puzzli

问题补充：

The question was so that there was a expression on the teachers face.

A. puzzled; puzzling

B. puzzled; puzzled

C. puzzling; puzzled

D. puzzling; puzzling

答案：

A. puzzled; puzzling

B. puzzled; puzzled

(答案→)C. puzzling; puzzled

D. puzzling; puzzling

解析：考查形容词。Puzzled困惑的，不解的; puzzling令人困惑的。句意：问题是如此的令人不解，以至于在老师的脸上带着一副困惑的表情。故C正确。