——There must be a dozen pens in this house but I can never find one when I need one.——Keep looking. is sure to turn up.
75. Taiji boxing is good _____ health, so the old man began to practise it ten years ago and now he is good _____ it.
74. We went _____ our plan carefully before we carried it out.
73. It is not right _____ a person who is _____ trouble.
72. We couldn’t read the notice on the board because several people were standing _______ it.
71. People eat a lot of sugar __________ cakes, soft drinks, sweets and so on every day.