原式=1-a-1a×a(a+3)(a+1)(a-1)
=1-a+3a+1
=(a+1)-(a+3)a+1
=-2a+1．
最简单的交换排序方法是( )。
A．快速排序
B．选择排序
C．堆排序
D．冒泡排序
8.Jack wants to become a friend of _______ shares joys and hardships with him .
A．somebody
B．whomever
C．anybody
D．whoever
