From his expression we can guess that the problem maybe was quite .A. puzzled ; puzzlingB

问题补充：

From his expression, we can guess that the problem maybe was quite .

A. puzzled ; puzzling

B. puzzling; puzzled

C. puzzled; puzzled

D. puzzling; puzzling

答案：

(答案→)A. puzzled ; puzzling

B. puzzling; puzzled

C. puzzled; puzzled

D. puzzling; puzzling

解析：考查形容词用法。Puzzled困惑的，（常修饰人）；puzzling令人困惑的（常用来形容事物）。但是look, expression等与人有关的事物仍然用puzzled等过去分词转换的形容词修饰。句意：从他困惑的表情，我们能够猜想那个问题也许非常的令人困惑。根据句意说明A正确。