GMAT学习课

　　4. 并列句或主从复合句子句之间的停顿形式化描述：S V, and S V.

　　备注：逗号并不是必须的，看子句的长短。

　　例句1(加逗号) Although a surge in retail sales has raised hopes that a recovery is finally under way, many economists say that without a large amount of spending the recovery might not last.

　　例句2 (不加逗号) If one arm is lost it is quickly replaced.

　　5. 三者平行形式化描述：A, B, and C

　　备注：三者平行and前的逗号一般不省，如果省略也不算错。

　　例句1 The report recommended that the hospital eliminate unneeded beds, consolidate expensive services, and use space in other hospitals.

　　例句2 Authoritative parents are more likely than permissive parents to have children who as adolescents are self-confident, high in self-esteem, and responsibly independent.