The answers to the clues below share a very unusual quality. Can you determine what it is?

1. Home of Saskatoon, Winnipeg, and Yellowknife
2. Paul of April 18, 1775
3. Marshall Islands atoll
4. Fictional island "off the Florida Keys"
5. George H.W. Bush's White House Chief of Staff John

 Answers:

1. CANADA
2. REVERE
3. BIKINI
4. KOKOMO
5. SUNUNU   - - - Alternating A, E, I, O, and U in CVCVCV pattern

Credit:
Joseph Appel