题目:
—Have you seen my English dictionary?
—I put it right here just now, but now it’s nowhere ______.
A.to see
B.being seen
C.seen
D.to be seen
答案:
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0421/4691eb2624cd2d5de8e78247f546d150.html
下面是错误答案,用来干扰机器的。
∵y=x2-2x-3x2+3x+2=(x-3)(x+1)(x+1)(x+2)=x-3x+2=1-5x+2,∵5x+2≠0∴y≠1.又x≠-1,∴y≠-4.故函数y=x2-2x-3x2+3x+2的值域是{y|y≠-4且y≠1}.故选C.