Specimen可与sample换用，但常指人或物中选出的有代表性部分，或指供科研、化验或检验用的标本。 主要内容如下:分 析介绍了几种常见抽油泵的工作原理、构造 、 适用范围及分类. Enormous garbage dumps and sprawling landfills constitute one of the additional unpleasant impacts that human beings have on wildlife. During the previous times, applicants only had to post a sample of their faculty papers... https://housebuyingurgaon.blogspot.com/