Unit4ampnbspbigampnbspbusinessgrammar学案

　　unit4 big business-grammar学案
　　一．快捷识记
　　i． 过去分词作状语所表示的意义：
　　过去分词短语作状语，可表示时间，原因，条件等，可发展为一个状语从句。过去分词作状语可分为：
　　一般式 (done) 表示分词动作与谓语动作同时发生或分词动作发生于谓语动作之前。
　　完成式 (having been done) 强调分词动作发生在谓语动作之前。例如：
　　scolded (as she was scolded) by the teacher, the girl sat there without lifting her head.
　　由于被老师批评了，那个女孩低着头坐在那儿。
　　ii．过去分词作状语时的具体用法：
　　1．过去分词作时间状语相当于一个时间状语从句。例如：
　　asked (when he was asked) what had happened, he lowered his head.
　　当他被问问题的时候,他低下了头。
　　2．过去分词作原因状语相当于一个原因状语从句。例如：
　　frightened (=because / as she was frightened) by the tiger, the girl didn＂t dare to sleep alone.
　　因为害怕老虎, 这个女孩不敢单独睡觉。
　　3．过去分词作条件状语相当于一个条件状语从句。例如：
　　grown (if these seeds are grown) in rich soil, these seeds can grow fast.
　　如果种在肥沃的土壤里， 这些种子能长得很快。
　　given (if we were given) more time, we could do it better.
　　如果给我们更多时间的话，我们可以做得更好。
　　注意：此句中的given在许多语法书中作为介词处理。
　　4．过去分词作让步状语相当于一个让步状语从句。例如：
　　left (although he was left) at home, john didn＂t feel afraid at all.
　　虽然john被单独留在房间里, 他一点都不害怕。
　　5． 过去分词作状语表示伴随动作或状态。例如：
　　the teacher entered the classroom, (and he was) followed by a group of students.
　　老师进入教室，后面跟着一帮学生。
　　二. 练一练：
　　1. ________ in the queue for half an hour, tom suddenly realized that he had left his wallet at home.
　　a. to wait b. have waited
　　c. having waited d. to have waited
　　2. ________ by the beauty of nature, the girl from london decided to spend another two days on the farm.
　　a. attracting b. attracted
　　c. to be attracted d. having attracted
　　3. the research is so designed that once ________ nothing can be done to change it.
　　a. begins b. having begun
　　c. beginning d. begun
　　4. ________ to sunlight for too much time will do harm to one＂s skin.
　　a. exposed b. having exposed
　　c. being exposed d. after being exposed
　　5. price of daily goods ________ through a computer can be lower than store prices.
　　a. are bought b. bought
　　c. been bought d. buying
　　参考答案： 1—5 cbdcb