解析：根据nineteenth century定位到文中第二段......The impetus behind the development of these early plastics was generated by a number of factors- immense technological progress in the domain of chemistry，.......其中，in the field of意思等同于in the domain of“在....领域”，因此答案为chemistry。

　　2. C6T1P3 In recent years， many of them have been obliged to give up their _____ lifestyle， but they continue to depend mainly on _____ for their food and clothes.

　　解析：根据上下文定位到文中Over the past 40 years， most have abandoned their nomadic ways and settled in the territory's 18 isolated communities， but they still rely heavily on nature to provide food and clothing. 本题的替换很明显也很简单，因为大多数同学都认识abandon， 更知道give up是“放弃”的意思，属于单词与词组的替换，因此第一个空填nomadic， lifestyle“生活方式”与ways替换，depend mainly on与rely heavily on属于词组与词组的替换，意为“依赖......”，答案为nature。

　　3. C6T4P3 Playground supervision will be more effective if members of staff are trained to recognise the difference between bullying and mere______.

　　解析：根据上下文定位到文中E段最后Work in the playground is important， too. One helpful step is to train lunchtime supervisors to distinguish bullying from playful fighting.题中句型为recognise the difference between A and B“区分A与B”， 文中句型为distinguish A from B， 同义，答案为playful fighting。

　　(四)主动语态和被动语态的转化

　　1. C5T1P1 As a reward for his hard work， he was granted a _____ by the king.

　　解析：根据the king定位到文中最后一段The Dictionary， together with his other writing， made Johnson famous and so well esteemed that his friends were able to prevail upon King George III to offer him a pension. 被动语态的基本结构：主语+be+动词过去分词+by， 与文中主动语态对应上，答案为pension“养老金，退休金”。

　　2. C7T1P1 Radar is an inaccurate term when referring to bats because _____ are not used in their navigation system.

　　解析：根据上下文定位到文中It is technically incorrect to talk about bat 'radar'， since they do not use radio waves. 很显然被动语态的主语在文中为主动语态的宾语，答案为radio waves。