Which sentences are simple sentences in the following paragraph?
The air show announcer hushed. He had been squawking all day, and now he quit. The crowd stilled. Even the children watched dumbstruck as the slow, black biplane buzzed its way around the air. Rahm made beauty with his whole body; it was pure pattern, and you could watch it happen. The plane moved every way a line can move, and it controlled three dimensions, so the line carved massive and subtle slits in the air like sculptures. The plane looped the loop, seeming to arch its back like a gymnast, it stalled, dropped and spun out of it climbing; it spiraled and knifed west on one side's wings and back east on another; it turned cartwheels, which must be physically impossible; it played with its own line like a cat with yarn. How did the pilot know where in the air he was? If he got lost, the ground would swat him.