Question

The boy and his friends ____(go) to Shanghai twice.

Answer 1

The boy and his friends go to Shanghai twice.
就近原则，看离得最近的一个词是单数还复数
但是如果用完成时的话，have gone就表示去了没有回来了，完成时的话就应该用have been,所以我觉得这里用现在时比较好

Answer 2

have gone
twice的话一般都用现在完成时，还有，这句话一点就近原则都没有，and表并列，主语是The boy and his friends所以用have。就近的词语一般是”not only，but also“ ”either or“ “neither nor” "or" "there be"这些

Answer 3

have gone

Answer 4

went