question: the primary thing to note here is that samsung's galaxy s9 plus has dual cameras and the 5.8-inch version doesn't. the galaxy s9 plus joins the galaxy note 8 as a dual-camera flagship devices.
Capitalize this past sentence correctly.
A: The primary thing to note here is that Samsung's Galaxy S9 Plus has dual cameras and the 5.8-inch version doesn't. The Galaxy S9 Plus joins the Galaxy Note 8 as a dual-camera flagship devices.

question: international cooperation - democracy-handbook.org
Capitalize this past sentence correctly.
A: International Cooperation - democracy-handbook.org

question: christmas comes early! time for new and exciting material.
Capitalize this past sentence correctly.
A: Christmas comes early! Time for new and exciting material.