Here are the correct answers for each sentence:

25. You should take regular exercise **B. instead of** sitting in front of the television all day.

26. High-level sport people must maintain a high level of fitness **D. even** run the risk of suffering injuries that cause permanent damage.

27. **C. unless** irritating they are, you shouldn't lose temper with small children.

28. There are **A. too numerous environmental problems** that not only governments but also individuals should join hand to tackle.

29. The second-hand car Patrick bought was almost new, **D. however** it was made in the 1990s.

30. "Did the minister approve the building plans?" "Not really. He turned them down **C. provided** that the costs were too high."