Must be, might be,can't be, must have been, might have been, can't have been, should have been

 I think they might be a groupe of people, working for a charity in Africa.
They must have been de same colour in theur t-shirt, in this case orange, to native people recognais them how a member of the nongovernmental assotiation.
They should have been helping children in their diary routines taking care of their body. But the main problem is get water for drink or clean the body.
The government must be more implicate building news structures apropiates to live. This can't be possible in 2012. It can't have been passing.
In spite of this people are laughing, it might be  because seing members of  NGO Africania, concerned about his  life.
In this picture can't have been all de members, because some of them are having a tipically african party.
I hope that all the members of eoi summer course could come to visit us.