Medio Ambiente - G8

Read the descriptions of the 10 most polluted cities in the world - diez ciudades más contaminadas del mundo. 
http://mexico.cnn.com/planetacnn/2010/10/27/la-ciudad-de-mexico-un-foco-rojo

#1
Why is China unique?
Is Mexico City considered a dangerous place to live?
What type of pollution is most prevalent in Mexico City?

#2
Spending one day in Linfen is equivalent to smoking how many packs of cigarettes?
What are the two major causes of air pollution in Linfen? (caused by = causado por)
Where is Tianjin located?
China is responsible for 18% of what?

#3
plomo=lead
What is the main form of pollution in Oroyo, Peru?
What is the cause of the pollution in Oroyo, Peru?

#4
What is unique about the River Citarum in Indonesia?
Do many people use this river for their water source?
Is Bandung the biggest city in Indonesia?

#5