透老空若有有害气体益出时，应立即用（）封闭。
A.钻杆
B.木塞
C.黄泥
参考答案：C
The Science Museum,______ we visited during a recent trip to Britain,is one of London's tourist
attractions. [ ]
A. which
B. what
C. that
D. where
* * 部位的脓肿
A．放射形切开B．沿皮肤的自然纹理切C．从侧方切开D．横形切开E．纵形切开
