The litter baskets were empty 为什么empty不是过去式

empty the listen,empty的过去式, The house of which the windows were broken was empty. 英语单词 的过去式empty sweep 什么the bottle empty empty the 倒垃圾. The bag is empty empty the bottle The function define empty! litter baskets have been placed under the trees为什么不用has the city is so empty empty the trash如何读