Which of the following are examples of primary sources?
*hint there are three*
a diary entry about the 1905 revolution in russia from a participant of the marches.
your school textbooks.
a speech given by a united states president.
a newspaper article from the day we entered wwi.
an encyclopedia entry about d-day.
a scholarly research article about imperialism's impact in today's world.

A primary source is written by the ones who participated in or observed the event.

So, out of the following, the three examples of a primary source are..

— A diary entry about the 1905 Revolution in Russia from a participant of the marches

— A speech given by a United States President

And, lastly,

— A Newspaper article from the day we entered WWI

I hope this helps, apologies if any of them are incorrect. Have a great day!