She_____because she wants to buy electricity in packets like sweets.
A:smells well
B:feels worse
C:looks foolish
D:finds out
一个圆环,外圆半径是6厘米,内圆半径是4厘米,圆环面积是____平方厘米。
在区间0,9上随机取一实数x,则该实数x满足不等式1≤log2x≤2的概率为( )