... states, and governmental units Des Moines, Iowa; Barrow, Alaska; Republic of South Africastreets, highways, and roads Grand Avenue, Interstate 29, Deadwood Roadlandmarks and geographical ... the Garden state Parkway, a main highway in New Jersey. b. I have traveled on the Garden State Parkway, a main highway in New Jersey.Proper AdjectivesProper adjectives are adjectives—that ... QUESTION MARKS, AND EXCLAMATION POINTS–Rules for Using Periods■ Use a period after an initial and after every part of an abbreviation, unless the abbreviation has become an acronym—an abbreviation...