主动脉瓣狭窄（）

A．心尖区舒张中晚期隆隆样杂音

B．心尖区全收缩期吹风样杂音

C．胸骨左缘第3肋间舒张早期叹气样杂音

D．胸骨右缘第2肋间3/6级以上收缩期吹风样杂音

E．心尖区柔和的收缩期吹风样杂音

--- You can use MSN to talk with Vivien on the Internet.

--- I know. But can you tell me ________?

A．when I can use it

B．what I can use it

C．why can I use it

D．how can I use it