英语翻译----- the reason that you ---- ---- going to Shanghai on

答案：(What's) the reason that you (are against) going to Shanghai on vacation?
oppose to (doing) sth = object to (doing) sth,它们都有“反对（做）某事”的意思,但是这些短语高中才能学到；
所以,建议填入are against.
be against (doing) sth也有此意.