US traffic signals didn't always contain the familiar three lights (red, yellow, and green). Traffic lights only red and green lights until the three-light traffic signal was developed in the 1920s.<br/><br/>Which choice completes the text with the most logical and precise word or phrase?
MM
Mashaal Masha
Jan 12, 2024
US traffic signals didn't always contain the familiar three lights (red, yellow, and green). Traffic lights only ______ red and green lights until the three-light traffic signal was developed in the 1920s.
Which choice completes the text with the most logical and precise word or phrase?