31.   The answer is not known.

32.   By the time this book is published, I shall know the answer.

33.   I think they know the answer.

34.   She suspected she knew the answer to that second question.

35.   She knew the answer to that one without even asking the question.

36.   Suddenly she knew the answer, even as she asked herself the question, and realised what she had to do.

37.   We know the answers to the first two and possibly the third as well.

38.   I wish I knew the answer.

39.   I know the answer I will always get, but I work on the dripping water principle.

40.   Everything is simple when you know the answer.