1) i did / was doing my homework when my sister came / was coming into the room
2) John and his sister walked / were walking to school when the accident happened / was happening
3) i talked / was talking about Kiki when she phoned / was phoning me.
4) while anna tidied / was tidying up her room, she found / was finding her watch
5) while alison studied / was studying , she remembered / was remembering it was her mum`s birthday
6) when we found / were finding out about the accident , we watched / were watching TV
Объяснение:
жирным выделены верные варианты
2-in order to avoid pollution u need to buy enviromentally friendly goods
3-ppl should stop building factories
4-stop smoking
5- stop a process of deforestation
6-don't set fire to the forest
7-don't leave unnecessary things outside
8-you need to plant a lot of trees all over the world to avoid the air pollution
9-create some departments that'd control a process of cleaning in every region of our country