A:城市化水平体现其社会经济发展水平
B:发展中国家城市化水平低,目前城市化进程比发达国家慢
C:城市化带动区域经济发展
D:区域经济发展促进城市化进程
在﹣227,0,﹣0.010010001…,π四个数中,有理数有____ 个.
—China's first large passenger plane C919 flew successfully on May 5.
—Yes. What's more, it was built on our own in Shanghai.