in most of the world's cities that

in most of the world's cities that monitor outdoor air pollution

Results (Chinese) 1:

在大多数的室外空气污染监测的世界的城市

Results (Chinese) 2:

在大多数监测室外空气污染是世界上城市

Results (Chinese) 3:

在大多数的世界城市，监测室外空气污染