What happens here is we re-call the function to run with the starting variables, and we also add the "thing_speed" (which is 7 pixels that it moves each time) to the y position, thing_starty, of the block. So, at 60 FPS, we move the block down 7 pixels each frame.If we just stopped here, we'd find that only 1 block is generated, and, once it has passed us, it will just keep going forever. We need some handling, like the handling we used with our car, to create another block once one has moved off of the screen.That is where: