B
Uh-huh.
A
-- that would take the air from the outside and clean the air before it would get into the house --
B
My goodness.
A
-- and so it was quite a dirty city. Um, if you were well protected by trees, which catch a lot of the pollution --
B
Uh-huh.
A
-- then you're fine, but most of the time in the city you have lots of high rises, you have lots of other things that are not catching the pollution and it's just going --