Useful sites for studying English.

1. PBS
To provide sound, script. This is for IBT Toefl listening.

2. Flash Animation 
To prvide background knowledge for IBT Toefl listening and reading.

3. Brightstorm
To help math for GRE

4. Morecular Expressions
To show microscopic images, such as flea...

5. 60 seconds
This site provides sounds and scripts. Great!