硝酸甘油对哪类血管扩张作用最弱（）
A.小动脉
B.冠状动脉
C.小静脉
D.毛细血管括约肌
参考答案：D
He asked me _____. [ ]
A. who did kick the first goal in the World Cup
B. when was the APEC meeting held
C. when China became a member of the WTO
D. where will the 2008 Olympics be held
物体做自由落体运动，则（）
A.第2s内的位移是9.8m
B.第2s内的位移是14.7m
C.第2s内的平均速度是9.8m/s
D.第2s内的平均速度是14.7m/s
