三种

• The graphic record shows three waves arriving one after the other at short intervals .
  图形记录显示了在短短的间隙内先后到达的三种波。
• For the primary classification of a set of entities, there are three types of decision to be made .
  对一组对象的初级分类，要作三种判断。
• The first two are both used for scientific problems and the third for business applications .
  前两种都是用于科学问题，而第三种则用于商业。
• We passed a rule that every employee had to be checked out on at least three operations .
  我们定了一条规矩，每个工人一定要经过三种工作的训练。
• There are three types of "formed" elements: the red blood cells, leucocytes, and the thrombocytes .
  有形成分有三种：红血细胞、白血细胞和血小板。
• The lithology is recorded together with the analytical results for each of three elements .
  岩石情况要与三种元素中每一种的分析结果一并记录下来。
• It is obvious that common to all methods is the need to determine two of the three volumes .
  显然所有方法的共同点是，都需要测量这三种体积中的两种。
• For measuring abrasion of catalyst particles, three basic attrition test apparatus are used .
  为了测定催化剂颗粒的磨损，可使用三种基本磨损测试装置。
• There are three main operations in the heat treatment of steel: hardening, tempering and annealing .
  钢的热处理操作主要有三种，即：淬火，回火和退火。
• Each of these life-sustaining agents begins as a stem cell, a sort of hematological embryo .
  这三种维持生命的要素都起源于干细胞。干细胞是血液的胚胎。