1·调查者比较了，有其中10种肿瘤的一种的4913例患者和3900例非肿瘤诊断的对照组。
The investigators compared 4913 patients who had any of 10 types of cancer with 3900 controls who were admitted for non-cancer diagnoses.
2·那么现在，我用75乘以52，结果是3,900，这就是一个普通人一生中所拥有的星期六的总天数。
Now then, I multiplied 75 times 52 and I came up with 3900 which is the number of Saturdays that the average person has in their entire lifetime.
3·群岛位于两个称为大小浅滩的半水下碳酸浅滩上，两个浅滩被一条3900米深的海峡隔开。
The archipelago rests over two slightly submerged carbonic banks known as the Great and Little Bank which are separated by channels that in deference reach depths of 3900 metres.