Why are these rejected images

I have attached the rejected images, the ones wich were accepted were very similar.

As the moderation is done by humans and the decision of acceptance and refusal is not an exact science. Some parameters are easy, like the resolution, exposure etc, some others may be measured like the noise level, some others like the white balance may not be always obvious. So it may well be that different moderators take different decisions. Even the same moderator may take different decisions based on human factors like the fatigue or the time of the day.

Deleting an accepted picture and resubmitting it may as well lead to a refusal the second time. And that may even be "justified" due to a changed moderation process or it may simply be dependant on other factors.

This said: most of my personal refusals are simply correct, because I did not see a defect on a picture or the image was out of focus and I was to eager to upload my 30 latest picture without taking the time to look into each image with the same consequence (for the same reasons a moderator may or may not refuse a picture).

If you are new to stock, you should consider these resources: https://helpx.adobe.com/stock/contributor/tutorials.html
Please read the contributor user manual for more information on Adobe stock contributions: https://helpx.adobe.com/stock/contributor/user-guide.html
See here for rejection reasons: https://helpx.adobe.com/stock/contributor/help/reasons-for-content-rejection.html
and especially quality and technical issues: https://helpx.adobe.com/stock/contributor/help/quality-and-technical-issues.html

#1 Watermarks are not acceptable.

#2 Perhaps the rejects were too similar to your other submissions. 

Adobe Stock looks for unique content as well as high visual & technical quality. See links below.
https://helpx.adobe.com/stock/contributor/help/reasons-for-content-rejection.html
https://helpx.adobe.com/stock/contributor/help/quality-and-technical-issues.html