For every article directory you join you need to take a good look at their terms of use and guidelines for submission. If your article was rejected you and they didnt tell you why then you need to read the article and the guidelines for submission and check what errors you made and just re-submit it.
first you read the article guide lines, you maintain quality content, don't use more than 3 hyper links.
There are some factors for rejection, Grammar mistake Copy content not relevant as per topic very less content more links in article not as per terms and condition or some one else has already submitted it or person with your user name may be band in article directory may be any one of factor
Content plays a main role in article submission you should provide a quality content so that you can minimize the rejection rate my friend!!!!!!!!!!!!!!!!!!!!!!!