27. Large sums of money (ought to keep) in a bank, didn't you think? 28. At our high school, the students' grades (send) to their parents four times each year. 29. I'm sorry, but the computer job is no longer available. A new programmer (hire, already). 30. Household cleaning agents (must use) with care. For example, mixing chlorine bleach with ammonia (can produce) toxic gases. 31. What products (manufacture) in your country? 32. Aluminium is a valuable metal that (can use) again and again. Because this metal (can recycle), aluminium cans (should throw away, not). 33. Endangered wildlife (must protect) from extinction. 34. People with the moral courage to fight against injustices (can find) in every corner of the world.

27. Large sums of money ought to be kept in a bank, didn't you think?

28. At our high school, the students' grades are sent to their parents four times each year.

29. I'm sorry, but the computer job is no longer available. A new programmer has already been hired.

30. Household cleaning agents must be used with care. For example, mixing chlorine bleach with ammonia can produce toxic gases.

31. What products are manufactured in your country?

32. Aluminium is a valuable metal that can be used again and again. Because this metal can be recycled, aluminium cans should not be thrown away.

33. Endangered wildlife must be protected from extinction.

34. People with the moral courage to fight against injustices can be found in every corner of the world.