—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
网友回答
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。