《12假如没有灰尘PPt.ppt

　　 * * Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 勿用　尘埃　湿漉漉　 彩虹 日晕　然而　面临　　 颗粒　来源　飘浮　削弱　　 柔和　性能　依附　稳定　　 单调 晚霞朝晖 庞然大物 气象万千 闲云迷雾 古往今来 学习词语 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 默读课文思考： 灰尘有什么特点和作用？ 作者是怎样说明这些特点和作用的？ Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 灰尘的特点 灰尘的作用 使用的说明方法 细小 散射光线 使阳光变柔和 假设 散射七色阳光 使天空由蓝变白 假设、作比较 吸湿性 调节气候，气象万千 假设、作比较 灰尘的特点作用 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 假如大气中没有灰尘， 假如大气中没有灰尘， 强烈的阳光将使人无法睁开眼睛。 由于只存在气体对阳光的散射， 整个天空将始终是蔚蓝的。 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 假如大气中没有灰尘， 假如大气中没有灰尘， 地面上的万物都将湿漉漉的。更严重的是，大气中的相对湿度不断上升，就会影响生物的生存。 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pt