square hysteresis loop material

例句：

1. 1.The room is square and has four walls.
   这个房间是正方形的，有四面墙。
2. 2. The square of a number is the product of its prime factors.
   一个数的平方是它的质因数乘积。
3. 3.The square root of 16 is 4.
   16的平方根是4。