And he found that cities with well-used libraries also have greater numbers of people who buy books online.

VOA: special.2009.03.27

If he switched from gold to let's say iron, he also tried platinum, a number of different foils, he found that they count rate it still was 20 alpha particles per minute.

金箔的时候，计数率就变成零了,如果他把金换成比如说铁，他们还尝试了铂,还有一系列其他的箔片，他发现计数率还是每分钟。

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