The noun Bible (capital B) is a proper noun as the title of the religious text of Christianity.
The noun bible (lower case b) is a common noun as a word for a book that is considered the most important one for a particular subject.
The singular possessive form is week's.
The singular possessive form is classmate's.
Bible's. For example, "The Bible's opening verse is God's creation of the universe."(The plural would be "Bibles'." For example, "We bought ten Bibles. The Bibles' binding was of fine leather.")
The possessive form is Amos's.
The singular possessive form for the noun gypsy is gypsy's.
The singular possessive form for country is county's.
The singular form for the plural noun countries is country; the singular possessive form is country's.
singular possessive: boy'splural possessive: boys'
The singular possessive form is speculum's.
The singular possessive form is aircraft's.
The singular possessive form is frontiersman's.
The singular possessive form is contralto's.