1. She'd live in London if she knew someone there 

2. I'd live in the country if I can find a job there 
3. If I had a spare ticket, I could (would cũng được nha)  take you to the concert 

4. If the children had watered some seeds (which they sowed), they would have grown 

(Câu này thì theo mình là nên thêm vào "which they sowed " cho đủ nghĩa, nhưng nếu bạn ghi bỏ cụm đó cũng được nha)

5. If they understood the problem, they would find a solution 
6. If he didn't sit around too much, I would be fit 
7. If Carol had not been studying, she would have answered the phone 
8. If Rita had got some sleep last night, she wouldn't be exhausted today 
9. If she weren't thin, she wouldn't feel cold so much 
10. If he polished his shoes, he would look smart 
11. If he could park near his office, he would come by car