Four teenagers standing next to a bus and talking and laughing .
Four teenagers are quiet and have somber expressions .
Four teenagers standing next to a bus and talking and laughing.
Four teenagers are quiet and have somber expressions.
If people are talking, they are not quiet. If people are laughing, they do not have somber expressions.
If people are talking , they are not quiet . If people are laughing , they do not have somber expressions .