—What about the student in your class Mr. Wang?—The doctor said that sleep caused him po

问题补充：

—What about the student in your class, Mr. Wang?

—The doctor said that sleep caused him poor memory and poor concentration.

A. lacking of

B. lacked in

C. lacking

D. lack for

答案：

A. lacking of

B. lacked in

(答案→)C. lacking

D. lack for

解析：本题考查非谓语动词中的动名词短语做主语。lacking sleep在句中作主语。