Basic

"If you had a dollar," quizzed the teacher, "and you asked your father for another dollar and fifty cents, how much money would you have?"
"One dollar." answered little Johnny.
"You don't know your basic math." said the teacher shaking her head, disappointed.
Little Johnny shook his head too, "You don't know my daddy."
Why do earth science professors always talk about ammonia? Because it’s basic material.
Why do Earth Science professors like to teach about ammonia?
Because it's basic material.
The basic rule in the bowling game is to ensure you leave no pin standing.