What's going on?
发生了什么事?
比如说你要用电脑,可是不知为什么无法开机,你就可以说 "Hey, what's going on?" 虽然这句话就完全等于 "What happened?" 或是 "What's up with that?" 但是老美还是比较喜欢说 "What's going on?" 又比如人家问你:"Why is our oven broken?" 你就可以推的一干二净地说:"I don't know what's going on (我不知发生了什么事)."