正方形的边长是x厘米,它的周长是______厘米,面积是______平方厘米.
正方形的周长=边长×4=4x;
正方形的面积=边长乘边长=x•x=x2;
故答案为:4x,x2.
It is widely acknowledged that students should be in terms of overall quality.
A.supported
B.matched
C.evaluated
D.controlled
()负载,其电流波形超前于电压,功率因数小于1。