宝宝正在学走路，总是摔倒在地上。

The baby is learning to walk and keeps falling on her ___butt.

长途徒步后，我的屁股因坐在粗糙的石头上而酸痛。

After the long hike, my ___butt was sore from sitting on rough rocks.

他在冰上滑倒，直接摔了个屁股墩儿。

He slipped on the ice and landed directly on his ___butt.