一氧化碳比氧气同血液中血红素亲合力大（）倍。
A.100
B.300
C.600
D.1000
参考答案：B
—I'm sorry I left my homework at home.
—_______.[ ]
A. You're right
B. Certainly
C. It doesn't matter
冷灰斗至折焰角管束采用内螺纹管作用？
