New Hampshire, New Jersey, New Mexico, New York
Missouri, Mississippi
North Dakota, South Dakota
North Carolina, South Carolina
Montana, Indiana, Louisana
Virginia, West Virginia
Maryland, Rhode Island
Wisconsin , Connecticut
North Carolina, North Dakota
South Carolina, South Dakota
Arkansas, Kansas
California, Virginia, West Virginia, Pennsylvania
Minnesota, North Dakota, South Dakota
Mississippi & Tennessee
bookkeeper
3. Actually, it is the only English word with 3 sets of double letters in a row.
The English word BOOKKEEPING or BOOKKEEPER has three sets of consecutive double letters. SUBBOOKKEEPER is the only word with four sets of consecutive double letters, although these words should be hyphenated.
Mississippi
The only one I can think of is bookkeeper. Are there others?
Mississippi & Tennessee
Mississippi
Well, there's probably more than three. Right now I could only think of "balloon" and raccoon though, assuming that you meant those double letters have to be next to each other.
successfully
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Bookkeeper