在2015年1月11日的
解析：
本文属于生物类文章，关注的是动物行为。在TPO中不乏相关题材的，比如TPO26第二篇就关注的是动植物在沙漠中的生存，所以背景知识学生不会陌生。在阅读过程中，学员需要额外关注不同方法的实现方式，并理清各个例子与观点之间的关系。
第一个传染阶段，主要是由于医疗差，人口发展，开始农业，人与人，以及动物之间的接触越来越多，疾病开始大规模的传染。第二，医疗得以发展，传染病被克服，但是由于经济的发展，生活水平不断上升，慢性病开始占据主导地位，比如心脏病，肺结核等。第三，到了现代社会，传染病重新出现，慢性病也没有被克服，细菌产生了抗力，很多以前没有出现的疾病开始出现了。
参考阅读：
Diapause, when referencing animal dormancy, is the delay in development in response to regularly and recurring periods of adverse environmental conditions. It is considered to be a physiological state of dormancy with very specific initiating and inhibiting conditions. Diapause is a mechanism used as a means to survive predictable, unfavorable environmental conditions, such as temperature extremes, drought or reduced food availability. Diapause is most often observed in arthropods, especially insects, and in the embryos of many of the oviparous species of fish in the order Cyprinodontiformes. (Diapause does not occur in embryos of the viviparous and ovoviviparous species of Cyprinodontiformes.)
Diapause is not only induced in an organism by specific stimuli or conditions, but once it is initiated, only certain other stimuli are capable of bringing the organism out of diapause. The latter feature is essential in distinguishing diapause as a different phenomenon from other forms of dormancy such as stratification, and hibernation.
Activity levels of diapausing stages can vary considerably among species. Diapause may occur in a completely immobile stage, such as the pupae and eggs, or it may occur in very active stages that undergo extensive migrations, such as the adult Monarch butterfly, Danaus plexippus. In cases where the insect remains active, feeding is reduced and reproductive development is slowed or halted.
(编辑：Sally)