Section
[C] any of the parts into which sth may be or has been divided 部分
【Eg】: This section of the road is closed. 这段路已经封闭.
[C] any one of a number of parts that can be fitted together to make a structure
部件; 零件
【Eg】: : the three sections of a fishing-rod
钓鱼杆的三节
[C] department of an organization, institution, etc （组织﹑ 机构等的）部门, 处, 科, 组, 股:
Sector
part or branch of a particular area of activity, esp of a country's economy
（活动领域的）部门; （尤指）经济领域
【Eg】: : the manu`facturing sector,
ie all the manufacturing industries of a country 制造业
Segment
(b) part of sth separated or marked off from the other parts; part of sth
that can be separated off in the mind 分出的或标出的一部分; 想像中可分出的一部分
【Eg】:: She cleaned a small segment of the painting.
她把画儿上的一小部分擦乾净了.
引用【牛津高阶英汉双解词典】
