When should common nouns be capitalized ?

This device blocks an opening along the base/floor of stairs or other walking or working surfaces where materials or body parts might otherwise inadvertently fall through. it should be 4 inches high, with not more than ¼ inch clearance above the floor

In the space below, enter the three discussion question stems you selected, and the answers you wrote as you reread the speech. even though this was a note-taking exercise, the answers should still be complete sentences, with correct spelling and punctuation.

Фthe sort the line that we can do \