用英语翻译:这个会议如此重要他不得不去参加

This meeting is too important to absent for him.
too...to 结构：太..而不能...
absent：缺席

This meeting is so important that he cannot but to attend
谢谢，欢迎采纳！

This meeting is so important that he has to attend

这个会议如此重要他不得不去参加
This meeting is so important that he has to attend
=This is such an important meeting that he has to attend
=This is so important a meeting that he has to attend
有不会的可以再问我