CHAPTER PARTS OF SPEECH 2 Specific rules for using articles (1)Some cases where articles may be omitted. in the caption of a figure 图2-1典型数字计算机的方框图 Fig 2-1 Block diagram of typical digital computers (2 In the definition of a certain terminology or abstract noun。 速度是涉及大小和方向的矢量 Velocity is a vector quantity involving both magnitude and direction. But: A velocity may be resolved into components.CHAPTER I PARTS OF SPEECH 2、Specific rules for using articles ① in the caption of a figure 图2－1 典型数字计算机的方框图 Fig. 2-1 Block diagram of typical digital computers. ② In the definition of a certain terminology or abstract noun. 速度是涉及大小和方向的矢量。 Velocity is a vector quantity involving both magnitude and direction. (But: A velocity may be resolved into components.) (1) Some cases where articles may be omitted