"他用法语跟我说话。" "你在开玩笑吧！真的吗？"

"He spoke to me in French." "___You're ___joking! Really?"

我家只有一台电视机？你一定是在开玩笑！我们需要四台电视机！

One television set in my house? ___You ___must ___be ___joking! We need four televisions!

"我以前从没吃过披萨。" "你一定是在开玩笑！"

"I've never eaten pizza before." "___You ___must ___be ___joking!"