急求大学英语(第三版)第三册作业2答案详解，包含所有单选题

12.athat/which关系代词，用于定语从句，前必有引导词（名词等），同时，that/which在定语从句中充当主语或宾语13.a14.b 用could 提问(1)表示请求的诚恳和礼貌时肯定回答为 Yes,I can.否定回答为 No,I can''t.(2)表示“可能”用于一般过去时态时，回答可用could.15.c 1.意思是：“要求、请求”时ask sb to do sth ,要求/请求某人做某事ask sb not to do sth ,要求某人不做某事2.意思为：“询问，查询”时ask sb about sth询问某人关于某事3.意思是：央求，要求时ask for+help,请求帮助16.c,见1217.c of which, which指代problems生活在澳大利亚沙漠的中心要面临一些问题，其中重要的一个就是取水问题。not least of =not the least of = a phrase used when you are giving an important reason for something, or an important example of something 部分的;尤其(用于陈述重要理由或举出重要例子)含最高级的否定比较句最常见的就是not the least of这一结构，常译为“其中重要的一个”，There were several reasons for dismissiqg him from his post，not the least of which was his neglect of duty．撤消他的职务的理由有几条，其中重要的一条是他玩忽职守。18.无答案（invited ，is allowed）invited过去分词（that was invited）is allowed 谓语动词，表被动主谓一致：主语为单数名词或代词，尽管后面跟有with, together with, except, but, like, as well as, rather than, more than, no less than, besides, including等引起的短语，谓语动词仍用单数形式；若主语为复数，谓语用复数形式。该题主语是不定代词Nobody，不定代词作主语，谓语动词使用单数形式，19.a20.b technique-a particular way of doing sth技术；技巧;your practical ability in sth技能；技术；技巧technology-1.the study and use of science for practical purposes in industry,etc科技/技术的研究及应用；2.the scientific knowledge that is needed for a particular industry,etc科技；技术tactics 策略，战术，用兵术