Please help me find out why the following HTML5 code does not take effect?_html/css_WEB-ITnose

I recently found a book to learn HTML5. There is an example in the book, which says that it will run normally in Chrome 10 (my Chrome is already version 18). The effect is to preview and display pictures in Chrome:

• Summary of Html knowledge
• How to learn HTML quickly
• The difference between html xhtml xml
• The difference between src and href attributes
• About HTML5 and CSS replacement use