—ThereisasmileonSam'sface.Hemustbe

问题详情：

—There is a smile on Sam's face. He must be ________ that his answer is right.

    —I think so. No one did as ________ as him in our class.

A. uncertain; well  B. certain; good           C. uncertain; good       D. certain; well

【回答】

D

知识点：相似 相近词比较

题型：选择题