Definition
This phrase is used to express that the answer to a question is so obvious that it is unnecessary to ask.
这还用问吗？
"Will he be attending the meeting?" "Is the Pope a Catholic? Of course, he will!"
「他会参加会议吗？」「教皇是天主教徒吗？当然会！」
"Do you like chocolate?" "Is the Pope a Catholic? Of course, I do!"
「你喜欢巧克力吗？」「教皇是天主教徒吗？当然喜欢！」
"Is the food good at this restaurant?" "Is the Pope a Catholic? This place has amazing food!"
「这家餐厅的食物好吃吗？」「教皇是天主教徒吗？这里的食物超棒！」