Zhao Jian (left), professor at School of Economics and Management, Beijing Jiaotong University.

赵坚(左)，教授，北京交通大学经济管理学院。

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Zhao Jian: Because there must be some time gap between each train. If the time difference is too small, they will crash. So, you cannot operate more trains on it.

赵坚：因为每辆列车之间必须有一些时间间隔，如果间隔过小，列车就会相撞，所以不能运行再多的列车。

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Zhao Jian: it has some function, but I think it is very limited.

赵坚：我认为有一些作用，但是很有限。

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When professor Zhao Jian, of Beijing Transportation University, publicly objected to the pace of high-speed-rail construction, Liu summoned him and advised him to keep quiet.

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"I think the bullet train system is not stable and may break down in extreme weather conditions, " said Professor Zhao Jian, a transportation expert with Beijing Jiaotong University.

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"In less than a decade, we constructed more high-speed rail lines than what it took Japan and Europe 40 years to build, " said Zhao Jian, an economics professor at Beijing Jiaotong University and one of the country's leading experts on rail transportation.

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