Thanks for replying my friend!...
But by the way, would you please explain the Time-sharing, Virtual machine processing, and virtual storage?..
I really need it because of our homework. Thanks again!...

Forgive me for being direct, but if you're doing this for homework, shouldn't you do some of your own research on the subjects of What Is virtual machines processing, time sharing, virtual storage, etc?
It is one thing to ask questions if OS/2 supports certain technologies within an OS/2 forum. It is another thing to ask people on that forum to do your homework for you. Where I'm from, having other people doing your homework for you is called plagiarism and generally will result in an F in any school/college/university I've gone to.
Some of these concepts you've asked about have been around for a long time within the computer industry. I'm sure you could visit a library, any decent text covering introduction to operating system concepts should cover these types of things. Failing that, you can always google.
Just my $0.02.