单项选择题
People eat a lot of sugar ______ cakes, soft drinks, sweets and so on every day.
单项选择题 Hearing a knock ______ the door, he hid himself ______ the door.
单项选择题 The monkey ______ the tree was eating the bananas ______ the tree.
单项选择题 Some new changes happened ______ the school ______ my absence.
