Barcelona:

• public transport ("There are a lot of buses here")
• cycles ("...people often walk or ride their bikes...")
• pollution ("I think that the pollution from transport is a really big problem")

Bogotá:

• pollution ("The idea is that there is less pollution")
• public transport ("...there were buses...")
• cycles ("The roads become cycle paths")

Singapore:

• animal life ("...and a butterfly farm" – очень даже считается, если нужно обязательно отнести каждую тему)
• pollution ("...there was a lot of pollution...")
• rubbish ("You can pick up the rubbish in your area")

Adelaide:

• pollution ("I didn't think Australia had a lot of pollution")
• parks ("There are 29 parks")
• recycling ("...which recycles its energy and water")
• cycles ("Also there are a lot of cycle paths")
• public transport ("There is a bus that doesn't use petrol")