各选项中()最符合变化规律
A.A
B.B
C.C
D.D
参考答案:C
解析:
三叉线顺时针每次旋转90度,黑点区域逆时针每次旋转90度,且一、三项有黑色区域,二、四项没有黑色区域。
—Now the air in our hometown is even ______ than it was before.
—So we must do something to stop it. [ ]
A. dirty
B. better
C. worse
D. more better
背景
问题
加强施工物资采购合同管理的意义何在