stack head

例句：

1. 1. The boxes are stacked neatly on the shelves.
   箱子整齐地堆放在架子上。
2. 2. He stacked the books in the corner of the room.
   他把书堆在房间的角落里。
3. 3. The workers were stacking crates to load onto the truck.
   工人们正在堆放集装箱准备装车。