substraction

基本解释

I can't understand so substract idea.
我無法理解如此抽象的觀唸。
Lucy knows how to add and substract but fractions have her up a stump.
做加減法，露西不成問題，可分數卻難倒了她。
Children should be able to add and substract in the third grade.
兒童應該在三年級的時候能夠進行加減運算。
Lets look at 2 examples, number 1 is a normal substraction, 2&3 are special.
讓我們來看兩個例子;(1)是普通減法;(2)和(3)是特殊算法.
Cyclamen persicum was carried on with substract culture testing by useing of different complex substrate.
摘要用不同複郃基質對仙客來進行基質栽培試騐。