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. The most up-to-date congressional report acknowledges the vital significance of technical schooling, but will also asserts the research of the humanities (人文学科)and social sciences have to remain central parts of Americ... https://gurgaonluxuryhouse.blogspot.com/2025/06/sanctuary-105-elegant-urban-living.html