若一个扇形的面积是12π,它的弧长是4π,则它的半径是______.
根据扇形面积s=12lr,得
12×4π×r=12π
解得r=6.
故答案为:6.
静脉输液纠正霍乱脱水时一般首选:()
A、生理盐水
B、葡萄糖水
C、葡萄糖盐水
D、复方氯化钠溶液
E、低渗盐水
The speed of cars and trucks is _____ 30 kilometers per hour in large cities in China. [ ]
A. limited
B. limiting
C. limiting to
D. limited to