what's

剑桥词典

short form of what is or what has
（what is 或 what has 的缩略形式）
What's (= what is) that stuff on your forehead ? 你前额上的是什么东西？
They want a list of what's (= what has) been stolen . 他们想要一个失窃物品的清单。 返回 what's