—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

下列哪种情况与诊断心肌病无关：（）

A.无明显症状，心电图异常

B.患者有单独心房扩大和二尖瓣返流

C.无症状，X线检查心脏扩大

D.同时有左右心室充血性心衰

E.自觉乏力，劳力性呼吸困难