单选题 Which of the following does NOT contain an adverbial clause of cause?

A、 Coward as he was, he ran back as soon as the enemy attacked.
B、 Inasmuch as he has confessed and apologized, we will forgive him for the wrongs he has done us.
C、 Clever as the boy was, he found some difficulty in solving the problem.
D、 Men differ from brutes in that they can think and speak.

【正确答案】 C

【答案解析】[解析] 状语从句。由as引导的原因状语从句可采用“主语补语或状语+as+主语+谓语动词”结构，只见于正式语体，A项就是此类用法；且根据上下文的意义，此结构可表示“虽然”，故C项中是让步状语从句。复杂从属连词inasmuch as和in that引导的也是原因状语从句，B项和D项都属此类。