21. you must have your blood tested if you are operated on.
22. if we add 72 and 28, we get 100.
23. i will not buy my brother the tortoise, it's too expensive.
24. if you have an earache tomorrow, you will have to go to a laryngologist.
25. i wouldn't be surprised if the boss came with his secretary.
26. if they don't have about 300 dollars, they won't buy new binoculars.
27. you will understand the instructions if you read them twice./you would understand the instructions if you read them twice.
28. if he is absent from school tomorrow, i will call his mother.
29. if it snows next week, we will go to zakopane.
30. you would catch up with him if you ran faster.
