1. The snake crawls on its belly.
    那条蛇匍匐而行。

2. As the turtle swims across the oceanarium, the first porpoise swoops down from above and butts his shell with his belly.
    当海龟游过水族馆时, 第一只海豚从上方猛扑下去, 并用腹部撞击龟壳.

3. The first porpoise swoops down from above and butts his shell with his belly.
    第一只海豚从上方猛扑下去，用腹部撞击龟壳。