Tittle:What squatter cities can teach us
https://www.ted.com/talks/stewart_brand_on_squatter_cities?utm_campaign=tedspread&utm_medium=referral&utm_source=tedcomshare

Good sentence
1)And here's the second punch line (the last few words of a joke or story, that make it funny or surprising).
ex)He is taller than us but he can not play the volleyball because he forgot to bring his shoes. This is punch line.

2)What's going on in the street in Mumbai?
ex)What's going on in this university?

3)Villages of the world are emptying out (To become devoid of people).
ex)I went the class room but there are emptying out.