diff --git a/Echo_Device/ppts/0_Echo_Show_Introduction.pptx b/Echo_Device/ppts/0_Echo_Show_Introduction.pptx index f6a6211..b489fe4 100644 Binary files a/Echo_Device/ppts/0_Echo_Show_Introduction.pptx and b/Echo_Device/ppts/0_Echo_Show_Introduction.pptx differ