抢救急性肺水肿病人加压吸氧时,湿化瓶内的酒精浓度是
A.10%~20%
B.20%~30%
C.30%~40%
D.40%~50%
E.50%~70%
参考答案:B
一元二次方程x2-3=0的根为______.
—Would you mind ________ my pet dog while I'm not at home?
—Of course not. [ ]
A. looking at
B. looking up
C. looking for
D. looking after