二尖瓣狭窄时提示肺动脉高压的体征是:()
A.开瓣音
B.心尖部舒张期杂音出现得晚
C.第一心音亢进
D.心界明显扩大
E.肺动脉瓣第二心音亢进、分裂
参考答案:E
He spends all his free time _______ computer games. [ ]
A. in
B. on
C. for