diff --git a/assignments/.gitkeep b/assignments/.gitkeep
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-# Homework
-
-> 作业及参考解答
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diff --git a/exams/.gitkeep b/exams/.gitkeep
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diff --git a/exams/README.md b/exams/README.md
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-# Examination
-
-> 往年的考试题，以及模拟考试题。
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diff --git a/labs/.gitkeep b/labs/.gitkeep
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diff --git a/labs/README.md b/labs/README.md
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-
diff --git a/materials/.gitkeep b/materials/.gitkeep
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-# Learning Resources
-
-> 电子书和各种可供自学的资料
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diff --git a/notes/.gitkeep b/notes/.gitkeep
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-
diff --git a/slides/.gitkeep b/slides/.gitkeep
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diff --git a/slides/README.md b/slides/README.md
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-# Handouts
-
-> 课件、讲义、教师提供的参考资料等
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