The water shed of this river system takes up almost half of the United States and includes the Ohio, Missouri, and Mississippi Rivers

Ibelieve it's the pacific islands 

When two tectonic plates collide and one or both push upwards they also push up the crust,a mountain will for so that will be your answer. hoped this

Conflicts arising from drug cartels and goverment corruption is an issue that would most likely be considered as mexico's most challenging problem of today. the correct option among all the options that are given in the question is the third option or option "c". this problem has continued for a very long time.