柠檬脾气个人GMAT语法笔记,综合Manhattan SC及 prep语法笔记
（4）主系表结构的比较中，如果是主语比较，系动词要省略
According to a survey of graduating medical students conducted by the Association of American to plan to practice in socioeconomically deprived areas 错误
（5）as或than引导比较从句中的省略原则
1) 比较从句谓语与主句谓语相同，可用do，did，does代替。
2) 比较从句连系动词be与主句连系动词be相同，可以省略be，也可以不省略。
3) 主语谓语动词短语使用“助动词（如have，has，had，will）或情态动词（can，could，may，should）+verb”形式时，比较从句往往省略verb，保留助动词或情态动词。
4) 比较从句的主语和谓语与主句的主语和谓语相同时，可以全部省去，常常保留做状语的介词短语或状语从句。
5) 比较从句的主语与主句主语相同，可以省略。
than可做连词，还可做代词（在作为比较连词的同时还指代主语）
e.g. Only seven people this century have been killed by the great white shark, the man-eater of the movies—fewer than have been killed by bee stings. （prep1-218）
Despite recent increases in sales and cash flow that have propelled automobile companies'
common stocks to new highs, several industry analysts expect automakers, in order to
错误
补充完整，to set …. than they have been setting. set前后形式不一致，不能省略
