The typical trench system in World War I consisted of a series of two, three, four, or more trench lines running parallel to each other and being at least 1 mile (1.6 km) in depth.

第一次世界大战时典型的堑壕体系由2至4条以至更多的一系列壕沟组成，壕沟之间彼此平行，而且纵深可以达到1英里（合1.6公里）。

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The Bretton Woods system fractured amid the inflationary pressures of the 1970s, around the time the rich world embarked on a three-decade process of financial liberalisation.

70年代布雷顿森林体系在巨大的通胀压力下瓦解，富裕国家在随后30年中走上了金融自由化道路。

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All three types of changes must be addressed to successfully model a real-world system.

要对现实世界系统建模，就必须处理好这所有3种变化类型。

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The Kumon method, which is used by three million pupils world-wide, uses an individualised system of learning.

BBC: Maths classes 'overcrowded'

Education Minister Leighton Andrews described it as a "world class" system for those aged three to 19.

BBC: Hwb: 'World class' claim for learning scheme in Wales

Three-time World Memory Champion Ben Pridmore invented a memory system, which he alone has mastered, that allowed him to memorize the precise order of 28 shuffled packs of playing cards in one hour.

CNN: How to train your mind to remember anything