This unit is added to a stack and the user can then walk the stack to undo each action.

这个单位会加入至堆叠，然后使用者可以查核堆叠行程以复原每个动作。

youdao

This unit is added to a stack and the user can then walk the stack to undo each action.

这个单位会加入至堆叠，然后使用者可以查核堆叠行程以复原每个动作。

youdao