permutation
n.排列；置换
Permutation is an ordered arrangement of the elements of a set.
排列是指集合元素的有序排序方式。
quadrant
n.象限；四分仪
quotient
n.商
A quotient is the number obtained by dividing one quantity by another.
商是通过将一个数除以另一个数得到的数字。
fraction
n.分数
decimal
adj.十进制的 n.小数
The metric system is a decimal system.
公制是一个十进制系统。
diameter
n.直径
ellipse
n.椭圆，椭圆形
radius
n.半径
A line segment that joins the center of a circle with any point on its circumference is a radius.
半径是指连接圆心和圆周上任意一点的线段。
vertical
adj.垂直的(perpendicular, upright)
Vertical communication happens between subordinates and superiors.
发生在上下级间的纵向沟通。
deduction
n.减
statistics
n.统计学；统计表
even
adj.偶数的
2,4,6,8 etc. are even numbers.
2,4,6,8等是偶数
odd
adj.奇数的，单数的
1,3,5,7 etc. are odd numbers.
1,3,5,7等是奇数。