两个因数相乘的积一定比这两个因数都大.______.(判断对错)
这种说法是错误的,
如4×0.5=2,2<4;
0.3×0.2=0.06,0.06<0.2<0.3.
故答案为:×.
MT/T768-1998《煤用双层伞形叶轮浮选机》标准规定叶轮线速度下降值不应超过()
A.1%
B.3%
C.5%
D.10%
“郑庄公与母”的故事见于()