It's a see-through treadmill with a see-through treadmill belt, so we can watch the animal's feet, and videotape them through the treadmill belt, to see how they move.
是个透明的跑步机，透明的跑步带 我们能观察动物们的脚，给它们录像 透过这个跑步带，看它们如何运动