MicrostockGroup

You are one brave lad - I'll give you that.... But that said, I don't think Istock is a very nice place to be for a young fellow like you.

Don't get lured in to all their sweetalk, expect to be underpayed, talked down to, getting your files rejected for no apparent reason etc...

No - actually, I would recommend you not to join, and instead to to some photoshosting sites with a freindly environment, where you can get some good feedbask on your photography.

Best!

I really think you need to realize that iStock is the lowest paying stock site and the hardest to get into. It's you're decision but I really think you need to learn a little more.
The floorboard has no commercial value. What would it be used for? The harsh dark shadow along the edge won't fly with iStock.

The girl with phone is fair but there really isn't much expression of emotion in the shot. Plus the lighting is not the greatest. There are way to many shots on-line that are much better to even consider submitting it. You got to realize that if it's already a well covered subject and great pictures already covering it then it won't get the light of day.

The thai sausages won't work either. There are way to many distractions in that shot. Your eye goes to the blue basket and wanders around the shot looking at all the other things that are unrelated to the focus of the shot...the saugages.

I like this one the best, but as luissantos84 said there are copyrights involved and there are again to many distractions.

I doubt the cemetery would make it either. It really has very little commercial value and there is the possibility they would reject it on copyright also because of the design on the headstones.

You need to make your shots simpler. You want your eye to go to the subject of the photo and not wander all over the place. Before you ever hit the shutter release you need to look for those distractions and remove them. Just pay attention to where your eye goes first and if it isn't on the main subject, it would never sell for that very reason. You need to learn the rule of thirds. Rather than me trying to explain it to you, google it. I'm sure there is a site out there that would explain it.

the problem on that crop is that you will crop a lot of the photo.. have any new shoots?

I think you are Thai, right? I read some Thai on a note next to the sausages. Don't to forget to remove that kind of stuff or you won't get accepted for copyright.
The girl's face is too flat. You could change that with a friend holding up a reflector in the sun and certainly not shoot her against a sunny background which will be overexposed. Don't crop her face on the chin: the composition is lousy this way. Portrait would have been better than landscape. Clone out her skin defects. Let her smile or express some emotion.