如果考虑这个事件的历史背景，我们就能理解事件为何发生。
If we see the event in its history background, we'll able to understand why it occurred.
If we see the event in its historical background, we'll able to understand why it occurred.
If we see the event in its historical background, we'll be able to understand why it occurred.
If we see the event in its history background, we'll be able to understand why it occurred.
考点：历史背景historical context / background；发生occur。
