diff --git a/journal/log_book_of_Yifan_XU.md b/journal/log_book_of_Yifan_XU.md
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 ## Histories of note and note-taking
 
-Some interesting histories of note and note-taking were introduced in the module 1, which are quite impressive. 
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+Some interesting histories of note and note-taking were introduced in the module 1, which are quite impressive. 
+
+## Exercice 01-1 : Gitlab Search
+Question: Which two files contain the character string "LE MOOC RECHERCHE REPRODUCTIBLE C'EST GENIAL" in GitLab repository https://app-learninglab.inria.fr/moocrr/gitlab/learning-lab/mooc-rr-exo1?
+
+- My answer (correct): 
+  - module1/exo1/aebef6b0a5.txt
+  - module1/exo1/f683bbad4b.txt
+
+- **Note**: 
+  1. just use the "search or jump to" at the top-right corner at the main interface of the project. 
+
+## Exercice 01-1 : Gitlab history
+Question: Go to the GitLab repository https://app-learninglab.inria.fr/moocrr/gitlab/learning-lab/mooc-rr-exo1. 
+Find for the file module1/exo2/readme.md and, using the blame or history functions of GitLab, retrieve the commit that added the title Helloworld Python.
+
+- My answer (correct):
+  - the commit number: 505c4e26afaeaae6f563fe8b593155ec9d6210ca
+  - the author of the commit: Arnaud Legrand
+
+- **Note**: 
+    1. find the objective file. 
+    2. click "history". 
+    3. see each modification, and find the target one. 
+    4. click "copy the commit SHA to clipboard" and see the author's name.
+
+## Exercice 01-2 : writing a markdown file
+
+Question: write a markdown file that has the same content as the given PDF file.
+
+- My answer (correct):
+  - I have wrote such markdown file in the required gitlab directory, and the result has been compred with the PDF file. They have the same content except a blank line. 
+
+- **Note**:
+  - the page "introduciton to markdown" is quite helpful. I learned it first before writing this markdown file.
+
+
+## Exercice 01-3 : write a log book
+
+This is what I am doing right now. Current time is June 11, 2025. I have finished the homework of module 1. The deadline for finishing the module 1 is June 13, 2025.
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