Rewrite the following sentences so that the second sentence means the same as the first one

1.Rewrite the following sentences so that the second sentence means the same as the first one

11.Did they give food to homeless people last year?

->Was...

12.Although the weather was bad,the football match was not canceled

->Despite......

16.Many rivers and lakes are poisoned.Factories produce waste and pour it into rivers and lakes

->because......

17.Plastic bags are a major source of waste.We should not throw plastic bags everywhere

->(so)

18.we won't hold the festival.It costs too much money

->If ....... 

19.the tortoise was running.the hare was sleeping

->(while)

20.the girl worked hard.Her stepmother wasn't happy

->(Although)