Ok i need you to focus in class and stop being on this app you should use your brain its there for a reason
Answer:
he sido
(I have been)
The sentence says that I think that _____the problem.
han sido is they have been
he sido is I have been
ha sido is he have been
The sentence is I so he sido is correct.
Maybe I got that wrong but
Hope that helps ;)
Answer:
bajamos .... .............
