A: Whenever I see someone else yawn , I start yawning too. B: I’ve heard that yawning is contagious. yawn vi. 打呵欠 n. 呵欠 A: How do you keep your finances in such good shape? B: I have an auditor check my books on a yearly basis. yearly a. 每年的，一年一度的 ad. 每年，一年一次地 A: that crop didn’t yield much this year. B: Maybe the weather was too warm. yield vi. 1.(to) 屈服，服从；2.倒霉，垮掉 vt. 1.产生，出产；2.让出，放弃 n. 产量，收益 A: How did my window get broken? B: I saw a youngster accidentally throw a baseball through it this morning. youngster n. 青年，年轻人；孩子