( ) 8 He has to go to Beijing tomorrow A so has his wife B s

so be sb 用在 上文的动词是“be动词”的情况
eg.my father is fine.so is my mother
so do/does/did sb 用在 上文的动词是“一般动词”的情况
eg.he like foot.so do i
so have/has/had sb 用在前面的时态是“完成式,过去完成式”等
eg.he has been to Singapore.so have i
但是这个句子中has to 是情态动词,不得不,而这个句子中的谓语是go,是一般动词.