But proving this has been difficult because snatching a sample of the Mona Lisa's face for chemical analysis is, unsurprisingly, frowned upon.

但要证明这一观点则十分困难，因为要刮下一小块蒙娜丽莎的脸作为化学分析样本是无论如何都不可能得到允许的。

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The design consisted of face-to-face interviews of a nationally representative sample of more than 10,000 adolescents aged 13 to 18, with an average age of 15.

研究小组采取面对面访谈的方式，对全国1万余名年龄在13至18岁之间（平均年龄15岁）有代表性的青少年进行了抽样调查。

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Then I sample the face, and use the bucket (assuming all the lines are closed - which they weren't) to fill the rest of the body, and a slight blue with a bit of the flesh color for the pants.

我在脸部取样，使用油漆桶(将设所有的线条都闭合了——其实不会)来填充剩余的身体部分，短裤使用带一些肉色的淡蓝色。

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Sample-size containers of face and bath and dish and laundry soap.

NEWYORKER: Shauntrelle

If found guilty Hock - whose B sample will be tested on 30 June - will face a two-year ban from the sport.

BBC: Hock tests positive for cocaine

The players have the right to request that their 'B' sample be tested, while the penalties they potentially face range from a warning to a two-year ban.

BBC: South Africa pair Ralepelle and Basson fail drug tests