His explanation was so confusing that I could hardly make any    of it at all.

A．meaning

B．sense

C．idea

D．significance

与颈动脉搏动一致的点头运动见于( )

A．三尖瓣关闭不全
B．二尖瓣狭窄
C．主动脉瓣关闭不全
D．主动脉瓣狭窄
E．室间隔缺损