The boy            most of his free time            computer games every day. [ ]

A. spent; play

B. spends; play

C. spent; doing

D. spends; playing

重度主动脉瓣反流时心尖部可存在

A．Graham Steell杂音
B．Austin Flint杂音
C．Durozier征
D．Traube征
E．DeMusset征