Who Is to Blame?

Something big happened! There's a strong, strange rotten egg smell coming from Mrs. Hippo's house, it's probably a gas leak! However, when the police, firefighters, and gas experts took turns, they could never find the problem! What the hell is going on? *** Welcome to click on the column for a series of stories about Xiong Zhuangzhuang and his friends: "This Winter is Warm", "Fairy Tales Under the Grapefruit Tree", "Mr. Cicada Has Heatstroke" Intention: I know safety knowledge!