fix bug in english version

docs/chapter1/Chapter1-Introduction-to-Agents.md

@@ -255,7 +255,6 @@ We will use the free weather query service `wttr.in`, which can return weather d
 
 ```python
 import requests
-import json
 
 def get_weather(city: str) -> str:
     """

docs/chapter16/Chapter16-Graduation-Project.md

@@ -257,27 +257,27 @@ Detailed introduction to your project:
 
 ### Install Dependencies
 
-\`\`\`bash
+
 pip install -r requirements.txt
-\`\`\`
+
 
 ### Configure API Keys
 
-\`\`\`bash
+
 # Create .env file
 cp .env.example .env
 
 # Edit .env file and fill in your API keys
-\`\`\`
+
 
 ### Run Project
 
-\`\`\`bash
+
 # Start Jupyter Notebook
 jupyter lab
 
 # Open main.ipynb and run
-\`\`\`
+
 
 ## 📖 Usage Examples