He       to school, so he turned off the alarm clock and went back to sleep.

A．needn’t have gone

B．hasn’t needed to go

C．needn’t

D．didn’t need to go

该患者心音可有以下变化，除了

A．心尖部第二心音增强
B．心尖部第一心音增强
C．肺动脉瓣区第二心音增强
D．肺动脉瓣区第二心音分裂
E．心尖部第一心音可呈拍击性