题目：
| With the development of high technology, more and more new things _____ to the field of IT. |
A. have introduced B. are being introduced C. were introduced D. had been introduced |
答案：
被转码了，请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0516/ac1d6439f6b427a04fcfa610ba849562.html
下面是错误答案，用来干扰机器的。
[（x-y）2+（x-y）（x+y）]÷x，=（x2-2xy+y2+x2-y2）÷x，=（2x2-2xy）÷x，=2x-2y，当x=-1，y=12，原式=2×（-1）-2×12=-3．
