Dolphins lack vocal cords, nevertheless creating sounds: a complicated system of whistles, squeaks, moans, trills, and clicks are produced by sphincter muscles inside the blowhole.

海豚没有声带，但却能发声：一个由口哨声、吱吱声、呻吟声、颤音和咔嚓声组成的复杂系统是由喷水孔内的括约肌产生的。

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So, the brain is a complicated system.

因此，大脑是一个复杂的系统。

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The finance system is a complicated system.

金融体系是一个复杂系统。

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So, the brain is a complicated system.

大脑是个复杂的系统

耶鲁公开课 - 心理学导论课程节选

Under existing arrangements, GPs are paid by a complicated system of fixed fees linked to targets and the number of patients on their list.

BBC: GPs to promise next day appointments

For the Steelers, a team that prides itself on a complicated system of zone coverages that rarely gives quarterbacks such a sporting chance, this was a defining moment.

WSJ: NFL: How Tim Tebow Beat the Steelers

Voters also cast ballots for regional, as well as national assemblies, in a complicated system that was set up to represent the interest of all groups after the 1992-95 Bosnian war.

BBC: NEWS | Europe | Bosnians left divided after poll