review 1teaching aims and demands: review the sentences and the words from unit 1 to unit 3.learn to sing: the music room.can use the sentences correctly.teaching materials: tape recorder ; some cards.teaching steps: step one warm-up/ review1. sing and perform the song: the music room.2. review the words.(1) let’s mime: close, open, clean, turn on, turn off, play, sweep, go…(2) point t building, classroom, computer, fan, light…(3) look and say: grade, class, bright, clean, music, music room, computer room, library, on duty, hot ….(4) let’s count: thirteen , fourteen, fifteen, sixteen, seventeen, eighteen ,nineteen, twenty, thirty, forty, fifty, sixty, seventy, eighty, ninety, a hundred. step tw presentation1.guess a riddlelisten to the tape twice and guess “what is it?”i have a big face.my face is black.teachers write on me.students look at me.2.learn to sing: it’s time to clean up.3. read and match.step 3 practicelook, think and say.step 4 activity after classmake a survey.