下面四幅地图的图幅面积相同,比例尺最小的是:
A:世界地图
B:安徽地图
C:中国地图
D:亚洲地图
— Air quality in our city is becoming worse and worse.—Yes. These days' PM2.5 readings are frightening. We must do something to ______air pollution.
抛物线y=(x+2)2+3的顶点坐标是( )