今天小编带来英语四级词汇pop考点归纳，希望能够对你有所帮助。
　　And scores of online discussion boards have popped up on which people discussnegative experiences tied to too much time on the Web.
　　英语四级译文:
　　网上突然出现了很多讨论区，专门讨论花太多时间上网的负面体验。
　　四级词汇讲解:
　　本句的主干是boards have popped up。on which引导的是以online discussion boards为先行词的定语从句，起补充说明作用，其中过去分词短语tied to too much time on the Web作negative experiences的后置定语，tied与negative experiences为被动关系。
　　pop up的意思是“突然出现，冒出来”。如:
　　After the rain, mushrooms seem to pop up overnight.
　　下过雨后，蘑菇似乎一夜之间就冒了出来。

　　tie...to...的意思是“使紧密结合”。如:
　　Our success is tied to you.我们是否成功和你紧密相关。
　　英语四级考点归纳:
　　过去分词短语作定语时，通常放在所修饰的词之后，实际上相当于一个定语从句。如:
　　※ These are problems left over by history.=These are problems thatlwhich axe left over byhistory.这些是历史遗留下来的问题。
　　※ I like the idea presented by my dad.=I like the idea that/which is presented by my dad.我喜欢爸爸提出的主意。
　　※ She is the first nurse trained by their country.=She is the first nurse that/who is trained bytheir country.她是她们*自己培养的首位护士。