用来制造记忆元件的磁性材料属于（）材料。
A、软磁
B、硬磁
C、矩磁
D、顺磁
参考答案：C
“肥皂泡厚度约为0.0000007m”用科学记数法表示此数为______．
Pandas like eating and elephants like eating .
A．leafs, grasses
B．leaves, grass
C．leaf, grass
D．leaves, grasses
