doing something you aleady know
出来 ------ it's horizontal, doing something nonexistent before 下来 ------ go down; doing something you aleady know 看不起 ------ I look down on you. .
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doing something you aleady know
做一些你已经知道的事情
以上为机器翻译结果，长、整句建议使用 人工翻译 。