Select all the apply Regional urban centers face these challenges.

lack of housing

pollution

population decline

population shift to rural areas i

nadequate services​

Did you know it's illegal to own only one guinea pig in switzerland?   : )

I'm guessing  a. diverse  because it shows a wide variety of many things.

The circumcenter is  equidistant  from each vertex of the triangle. the circumcenter is at the  intersection  of the  perpendicular bisectors  of the triangle's sides. the circumcenter of a right triangle falls on the side opposite the right  angle. the incenter  of a triangle is always inside it.