Build your vocabulary look at the words in blue in the

Build your vocabulary look at the words in blue in the text . Which two words are verbs ? Use the worlds to complete the sentences .
1)Shark don't often ______ humans
2) There are ____ 6000 wild tigers in the world
3) Some people are trying to _____ endangered animals
4) There are more people who die in ____ with chairs than with animals
5 Human _____ are changing the climate
6 There is a lot of _____in big cities