单选题 4.I hate______when people talk with their mouths full.
【正确答案】 D
【答案解析】考查it做形式宾语的用法。句意：我很讨厌人们在说话的时候嘴里塞满东西。句中it作形式宾语，真正的宾语是when people talk with their mouths full。故本题选D。