Question on geography hw please

Which ofbthe following is a characteristic shared by both brazil and mexico

Formidable obstacles of climate, terrain, and distance hinder exploitation of natural resources in russia. true false

Will give brainliest asaapppppppppppp plz im in a major hurry to finish which of these pairs of objects exerts the greatest gravitational force on each other? object 1 and object 3 object 4 and object 3 object 1 and object 4 object 4 and object 2