（1）cause and effect因果
（2）have a good/bad effect on sth.对……产生好的或坏的影响
重点短语
要点1 every four years
【例题】 The Browns go to the country every_______ weeks.
A. few B. several
C. the second D. some
解析:根据题意，此处意思是“每隔几星期布朗一家就会到乡下去”。每隔几天“every few days”；每隔几年“every few years”。
