sit/set/seat辨析
1. sit 不及物动；坐；就座；
sit-sat-sat-sitting
例句：
① He sat at the table writing a letter. (他坐在书桌旁写信。)
② Sit here until she comes back. (坐在这里等她回来。)
2. set 安置；下沉；点燃；出考题；定时；树立(榜样)
set-set-set-setting
例句：
① Tom, set the table for dinner. (Tom，摆好桌子准备吃饭。)
② He set the alarm for 6:00 in the morning. (他把闹钟定在早晨6点钟。)
③ My teacher set very difficult questions for the exam. (我们老师试题出得非常难。)
④The sun rises in the east and sets in the west. (太阳从东方升起从西方落下。)
3. seat 使坐；容纳
seat-seated-seated-seating
例句：
① The theater can seat at least 2000 people. (这家戏院至少能容纳2000人。)
② Please be seated. (请坐下。)此句等于Sit down please.
③ He seated himself next to her. (他坐在她的旁边。)
