A:缅甸
B:印度
C:印度尼西亚
D:巴基斯坦
实现我国人口与经济、社会、环境协调发展最关键的措施是 ( )
现在,人们通过____、____等,能直接观察到地球确实在围绕太阳公转。
For years,scientists have been worried about the ________ of air pollution on the earth's natural conditions. ( )