-Where is your father?-He (go) to work.He'll be back soon.

问题描述:

-Where is your father?-He (go) to work.He'll be back soon.
为什么这个空要填has gone而不填 went呢?

看语境,问父亲在哪里,后面的回答是去工作了,一会回来.所以用went这个过去时不合适(过去发生过的动作),而has gone则表示已经,且持续,符合后面"即将回来"的语境.