Hi, guys, I managed to find MBR using google, sorry for posting that question.

But the other questions such as
1)Is the Linux Kernel located in /boot/ or usr/src/ ?? What is the kernel source?

2)Where is the boot block for Lilo??

3)Please teach me how to list the content of a CD-ROM from the terminal using Knoppix.

I really got no clues to those questions, so please advise.