main IF amplifier

例句：

1. 1. The mainreason for the delay is due to theheavy traffic.
   延误的主要原因是由于交通拥堵。
2. 2. Themain goal of the project is to improvethe efficiency of production.
   该项目的主要目标是提高生产效率。
3. 3. The main character in the play isa young woman who dreams of becoming afamous actress.
   剧中的主要角色是一个年轻女子，她梦想成为一名著名的女演员。