"What happened?" is a common way to ask about an event in Engpsh. It is a simple question that can be used in a variety of situations to inquire about an event or situation.
"What's going on?" is another way to ask about an event in Engpsh, and it is a more informal way of asking the same question.
For example:
"What happened at the meeting this morning?"
"What's going on? I heard shouting from outside."
翻译：
"今天早上会议上发生了什么？"
"发生了什么事？我听到外面有人大喊。"
这类问句是英语中很常见的问法，可以用来询问事件或情况。"What happened?"和"What's going on?"都可以用来询问事件发生的情况，前者是正式用法，后者是非正式用法。