Thanks for reply sig!
There was a time warning popped right after I turned on my Mac... It said I might have problems for some of my programs to work because my time was set before 2008. And then I check on the date/time setting, it became June something in 2000... (I bought this MacBook Pro only a year ago!!!)
After I clicked "OK" for that time warning box, there were about 3-4 programs with weird names asking for "allow." Can't remember all of them, but after I click on deny for all of them, the internet didn't work at all. So I restarted the system, everything showed up again, but this time I clicked one "allow" for the last request from "awacsd", and then the internet worked.
I restarted the Mac again, and this time nothing showed up at all, and the time was back on track... Turn on the iPhoto and it looked fine... I really don't know what happened to this Mac... (shake head...)