杨鹏 长难句 题号030 疑问求解

hanaboj

  原句：
  Studies ( by Hargrave and Geen) estimated natural community grazing rates by measuring feeding rates of individual zooplankton species in the laboratory and then computing community grazing rates for field conditions using the known population density of grazers.

  杨鹏长难句的解释中说， and then后面省略了一个 by，请问在GMAT中这个by是否可以省略呢？

yuanhaowen

说一个比较常见的结构。I will play basketball and (will) swim tomorrow. 这里的will就省略掉了嘛，如果不省略就显得wordy呗

brfmzbjz

可以的
根据and这个平行marker
你可以选择and后面的部分 跟前面的by doing 平行
or 跟doing平行