primary event

例句：

1. 1. The primary eventin this story is the discovery of anew species.
   这个故事的主要事件是发现了一个新物种。
2. 2. The primary event for the next fewdays will be the election results.
   接下来几天的主要事件将是选举结果。
3. 3. Theprimary event that caused thefire was a power surge.
   导致火灾的主要原因是一次电力波动。