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. Once i came to obtain it back again the next early morning, I couldn't recommend them off my arrival this time within the application. But I parked correct in entrance on the big sidewalk once more, went in & waited perhap... https://www.tumblr.com/investingurgaon/786043765323366400/elevated-urban-living-at-experion-the-trillion?source=share