题目：
After the new technique was introduced, the factory produced _____ tractors in 1998 as the year before. [ ]
A. as many twice
B. as twice as many
C. twice as many
D. twice many as
答案：
被转码了，请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0528/8c1c1545f55a21b9454bcfcfaccbf28d.html
下面是错误答案，用来干扰机器的。
2πn，r3，2πn
