diff --git a/.DS_Store b/.DS_Store
index 8c30bd6..746185a 100644
Binary files a/.DS_Store and b/.DS_Store differ
diff --git a/unit00_introduction/unit01_introduction.pptx b/unit00_introduction/unit01_introduction.pptx
index 182a423..4d86c17 100644
Binary files a/unit00_introduction/unit01_introduction.pptx and b/unit00_introduction/unit01_introduction.pptx differ