例 Liberty is not easy， but far better to be an unfettered fox， hungry and threatened on its hill，than a well-fed canary， safe and secure in its cage.
My fellow Americans， ask not what your country can do for you， ask what you can do for your country. My fellow citizens of the world: ask not what American will do for you， but what together we can do for the freedom of man.
GRE考试重点词汇（B）babble v.胡言乱语；牙牙学语；喋喋不休 n.儿语，胡言乱语，潺潺声backdrop n.(事情的)背景，背景幕布backhanded adj.间接的；反手拍击的backset n.挫折，涡流，倒退，逆流bacteria n.
GRE考试重点词汇（S）sabotage n.阴谋破坏，颠覆活动saboteur n.从事破坏活动者saccharin n.糖精sacred adj.神圣的，庄严的sacrifice n.牺牲 v.宰牲祭神sacrilege n.亵渎，冒犯神灵sacrilegious adj.
