如V1导联R/S≥1，V5导联R/S≤1常见于
A．左前分支传导阻滞
B．左心室肥大
C．右心室肥大
D．左束支传导阻滞
E．左后分支传导阻滞
参考答案：C
—It's 10 o'clock now. I must go.
—It's raining heavily outside. Don't leave ______ it stops. [ ]
A. since
B. until
C. when
D. because
原料气为什么要脱硫？
