这起事故究竟是如何发生的至今仍是个谜？的翻译：Exactly how the accident happened so far is still a mystery? 什么意思？中文翻译英文，英文翻译中文，怎么说？

青云英语翻译

This is exactly how the accident happened is still a mystery?

Exactly how the accident happened so far is still a mystery?

Actually did this accident is how occur is still a riddle until now?

正在翻译，请等待...

Exactly how the accident happened so far is still a mystery?