English idioms related jokes 3q ~ ~ ~ ~

One day, a famous English teacher in China's teaching and auxiliary field boasted in class: "With my accomplishments, there is no idiom I don't know, even China idioms can't beat me!" So the students asked ............ a: A sea of people! Teacher: Small case, "a sea of people"! I find it difficult to pass. Teacher: Hum, "I feel very sad" C: Study hard and make progress every day! Teacher: "study hard and make progress every day" D: Half-hearted! Teacher: Simple, "half-hearted"! E: Look through the autumn water! Teacher: You can't beat me. "look through the autumn water"! Self: red face knows me? Teacher: It's too simple-"confidante"! G: What about Ma-Ma-Hu-Hu? Teacher: Hey, "so-so"! Xin: We are brothers, who follows who! Teacher: "Who and who are our brothers?" ! Teacher: "I don't care" Deck: Teacher, you must not know: Who said blue and whose! Teacher:? Um ... ok ... I think ... (ten minutes later) ... you really failed the exam ... What does this sentence mean?