题目

Let's go and have _______ his new CD. A . look at B . a look at C . a look D . the look at 答案：B代数式a+b+c是二次函数y=ax2+bx+c当x=11时y的值；代数式a-b+c是二次函数y=ax2+bx+c当x=-1-1时y的值；代数式4a+2b+c是二次函数y=ax2+bx+c当x=22时y的值；代数式4a-2b+c是二次函数y=ax2+bx+c当x=-2-2时y的值．