13. I suggest that you look for another job. = if
14. he lost his money simply because he wasn’t careful. = if
15. I haven’t much money,I cant buy any new clothes. = if
16. jim didn’t lend me any money,so I was unable to buy the car.  =if 
17. The temperature didn’t fall below zero last night,so the crops weren’t damaged. = if
18. Joah will stay at school because she doesn’t find any job before may.
19. Mary didn’t work hard enough, she failed the exam. = if
20. You don’t get a visa,you cant visit the US. =if
21, Elizabeth got a bad cough because she started smoking cigarettes.=if
22. Mr TOM didn’t prepare his speech carefully, so he did it very badly.
23.  The gardener didn’t water those plants yesterday, so they died.
24. Without the sun,there would be no kinds of energy. = if 
25. We got lost because we didn’t have a map. = if
26. He didn’t study hard so he failed in his examination. = if
27. I made that terrible mistake because I wasn’t thinking. = if
28. I bought the dog because my children wanted a pet. = if
29. Mr Mill lost his job because he was late everyday.
30. If I had known she was sick, I would have visited her. = Had….
31. You’d better not touch that switch. = if I