Answer:
Good examples of common knowledge (False)
Often materials published before 1923 (True)
Often US government documents (True)
Available for re-use without giving credit. (False)
Explanation:
Items in the public domain are published works which are not copyrighted or the copyright has expired. US government documents published for consumption by the public are not copyrighted.
Regarding the expiration of copyrights, according to the January 1, 1978 act of copyright, the copyright of works published on or after this date under the author's name expires 70 years after the author's death.
The authors of these works still have to be credited when they are quoted.
