71. People eat a lot of sugar __________ cakes, soft drinks, sweets and so on every day.

72. We couldn’t read the notice on the board because several people were standing _______ it.

73. It is not right _____ a person who is _____ trouble.

74. We went _____ our plan carefully before we carried it out.

75. Taiji boxing is good _____ health, so the old man began to practise it ten years ago and now he is good _____ it.

76. He cut the apple ________, and gave the big to his little sister.

77. Oh, sorry. A lighted cigarette burned a hole _____ my coat, and I have to change another one.

78. The form is very important. Please fill in the form _______ ink not _____ a pencil, Jack

79. I wrote to Mr. Green, _______ him _______ the lost case.

80. Last week, we had a meeting. I told the chairman that I couldn’t attend it for I had something important to do, but he insisted _____ my being present.