The adjective dual means double or twofold. Duel is a noun or verb referring to a fight or struggle.
Examples:
- In 1954 the U.S. Supreme Court ordered that the system of dual schools for whites and blacks be dismantled.
- In an 1804 duel in Weehawken, New Jersey, Aaron Burr shot and killed former Treasury Secretary Alexander Hamilton.
Practice:
a) An undeclared and mostly bloodless _____ was fought for the control of Indonesia's 3,000 islands.
b) Sidney Poitier has _____ American-Bahamian citizenship.

