Please capitalize where necessary: a supernova is an exploding star. they're merging of black holes and neutron stars and are among the most violent events in the universe.
A: A supernova is an exploding star. They're merging of black holes and neutron stars and are among the most violent events in the universe.

Please capitalize where necessary: author svend posted on 27. september 201519. december 2016 categories drawing, inktober tags #inktober, daily drawings, fountainpen, ink
A: Author Svend Posted on 27. September 201519. December 2016 Categories Drawing, InkTober Tags #inktober, daily drawings, fountainpen, ink

Please capitalize where necessary: using the clean air act, we will finalize our mobile source rules and provide a framework for continued improvements in that sector. we will build on the success of energy star to expand cost-saving energy conservation and efficiency programs.
A: Using the Clean Air Act, we will finalize our mobile source rules and provide a framework for continued improvements in that sector. We will build on the success of ENERGY STAR to expand cost-saving energy conservation and efficiency programs.

Please capitalize where necessary: all children under the age of 6 may stay free of charge when using existing bedding.
A:
All children under the age of 6 may stay free of charge when using existing bedding.