下面一组图像应考虑为()
A．正常的右侧冠状动脉
B．正常的左前降支
C．右侧冠状动脉钙化
D．左前降支钙化
E．左旋支钙化
参考答案：C
You can't imagine what difficulty we had _________ home in the snowstorm. [ ]
A. walked
B. walk
C. to walk
D. walking
