fill in each gap with an appropriate preposition
1)the teacher divided class four groups
2)he provide us a lot of useful information
3)the ground is covered trash you should clear all the trash
4)raw sewage is pumped directly the sea
5)they are trying to save the animals extinction
6)the world will end like a second-hand junk-yard
7)i am looking forward hearing from you
8)don't throw trash the water