I remembered _____ the door before I left the office, but forgot to turn off the lights.

Our school, _____ in 1943, will celebrate its 70th anniversary this year.

It’s cold in here. We must have the fire　　　　day and night. 

Since her only child passed away a few years ago, family has been a ________ topic for her.

_______ on the American Civil War, the book attracted a large number of readers when it was published.