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unit3Anupliftingpowersandexpression
1.sustain: 1) to make sth/sb continue to exist over a period of time (maintain)      e.g. The teacher tried to sustain the children’s interests.              老师努力维持孩子们的兴趣。P: 这些食物可以维持我们一周的食用。 The food will sustain us for a week.