Doctors believe Sam most likely had a teratoma - a type of tumour that contains hair and body organs but rarely occurs in the brain.

医生们相信，山姆的肿瘤很有可能是畸胎瘤——这是一种包含有毛发和身体器官的肿瘤，但极少见其发生于脑内。

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Similar kinds of perceptual biases in the visual system had been documented before, but rarely in real-world situations.

类似视觉系统存在的视觉偏差，在以前的文献中已有记载，但现实当中却不多见。

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If priests had their way, it would be shortly after the wedding ceremony-but recent studies show such advice is rarely heeded.

依照牧师所说，那就是结婚仪式之后。但是，最近研究表明，听这种劝告的人很少很少。

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It gave Netherlands coach Bert van Marwijk and his side a deserved victory, but one they rarely had to be at their best to secure against opponents that worked hard but lacked the composure to capitalise on the few chances that fell their way.

BBC: Netherlands 2-1 Slovakia

But rarely have we had so lucid an account by such an observant participant of what goes on behind the cloak of jury secrecy.

ECONOMIST: American juries

Tens of thousands protested on February 20th in various cities, but rarely clashed with the police, who had been ordered to give the protesters a wide berth.

ECONOMIST: The protest movement is damped down by the palace, as usual