A:图线甲是电阻R1的“U﹣I”关系图象
B:电源电压为12V
C:电阻R1的最小电功率为2.7W
D:滑动变阻器R2的最大阻值为30Ω
“m≤∫124-3x2dx”是“函数f(x)=2 x+12x+m 的值不小于4”的( )
红色降落伞有____个。
I'm very proud that Beijing is one of _______ cities in the world.