11. Scientists have carried out extensive research into renewable energy sources.
-> Extensive research into renewable energy sources has been carried out by scientists.
12. He bought such a lot of books that he couldn't read them all.
-> So he couldn't read all his books because he bought a lot of them.
13.You haven‘t done your homework, have you?
->lt's time you did your homework
14. Keeping calm is the secret oi passing your driving test.
->As long as you keep calm, you will pass your driving test.
15. She can’t get into the habit of studying every evening.
->She can' t get used to studying everyevening
16. Would l borrow your car tonight?
->Would you mind letting me drive your car tonight, dad?
17. She has worked as a secretary since she lelt school.
-> She began working as a secretary when she left school.
18. Although Tom eats a lot of chocolate, he never puts on weight.
-->In spite of Tom eating a lot of chocolate he never puts on weight.