The first involves sheep. Researchers have found that hair sheep are a good source of blood for use in tests to diagnose infectious diseases in people.

VOA: special.2009.08.03

They use food frequency questionnaires, which I mentioned before, surveys, and then biological markers like blood tests of certain things to see how diet is related to health.

研究员还运用食物频率调查表,我之前曾提到过,各类调查以及生物标志物,像是血液检测等手段,来研究饮食与健康之间的关系

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

Are students allowed to use books when taking tests?

学生在参加考试的时候允许看书吗？

考试应该这么准备 - SpeakingMax英语口语达人

So tests often use human blood instead.

VOA: special.2009.08.03

Otherwise, we don't have enough seats, or we don't have enough test papers and so on. By the way, on the tests, you will be getting tomorrow these handouts that you can use in working the homeworks , so when you are taking the test, you are allowed to bring in the copy of the periodic table of the elements.

否则，我们就没有足够的座位，或者没有足够的考试卷子,顺便说一下，在测试当中，你们明天会拿到这些讲义,就可以用来做作业了,当你们在做测试时，你们可以带来,元素周期表。

麻省理工公开课 - 固态化学导论课程节选

A spokesman for the group says CT scans are frequently used in hospital emergency rooms because the results can be read quicker than with other tests, like ultrasound or MRIs, that do not use radiation.

VOA: standard.2010.01.30