Well, that's because the wheel, well, there's an assumption which is that the wheel is rolling on something normal like a road, and not on, maybe, ice, or something like that.
因为这是一个车轮,有一个前提假设,就是这个车轮是在常规路面上滚动的,而不是在冰面上,或者类似地。
3
Both of them could now see the wheelwell wedged between the rails and the uneven track bed.