关节盘穿孔破裂时弹响杂音的特点是()

A．开口初闭口末清脆单声响声

B．多声破碎杂音

C．一般无弹响杂音

D．开口末闭口初清脆单声弹响

E．多声清脆弹响

They think the room is________, but as a matter of fact it is already occupied. 

A．vacant

B．bare

C．blank

D．hollow