Please recommend jokes, healthy and civilized ones

A foreigner was eating with his Chinese friends. A Chinese friend said: "You guys eat first, I will go and make it convenient." The foreigner asked in confusion: "What is convenience?" Another Chinese friend The friend said: "Just go to WC." Another Chinese friend of the foreigner called and said: "If it is convenient for you, can we have a meal together?" The foreigner said: "No, I never do it when it is convenient for me." Eat."