• 练习 . 把下列句子变成被动语态。 1.My brother opens the windows every morning. 2.She didn’t clean the room this morning. 3. He bought his children some pencils. 4Mary is making a doll. 5. He hasn’t received the letter. 6. we often hear him sing. 7.Everybody will know the truth soon. 8.Her mother often makes her play the piano for long time.