问题补充:
There was a look on his face. He found what the expert said too difficult to understand.
A. puzzle
B. puzzling
C. puzzled
D. to puzzle
答案:
A. puzzle
B. puzzling
(答案→)C. puzzled
D. to puzzle
解析:puzzled形容词可以用来形容人,也可形容人的声音或表情。“他脸上带着困惑的表情,他发现专家所说的内容太难理解。”