engine引擎

1)In the past few years, investment was the engine of China's economy, whereas today it's mainly driven by consumption.(过去几年投资是中国经济的引擎，现在主要是消费在拉动中国经济)

2)Many technology companies have always been the engine of the Shenzhen economy.(众多科技企业一直是深圳经济的引擎)

3)直播写邮件

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    To whom it may concern:

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