Complete the second sentence so that it has similar meaning to the first sentence

Complete the second sentence so that it has similar meaning to the first sentence.(1.0 point)
1. Students are more aware of protecting the environment. Teachers teach environmental issues at school.
If ........................................................................................
2.People speak English all over the world.
English ........................................................................................
3.Many rivers and lakes are poisoned.Factories produce waste and pour it into rivers and lakes.
Because ........................................................................................
4. They provided food then cleared up the debris. 
After they ........................................................................................