In this task, we ask you to rewrite a sentence in simple English without changing its general meaning. Essentially, you want to make the sentence easier to read by using simpler words, utilizing more straightforward sentence structures, and omitting non-essential information etc.

In the oxygen- and sulfur-containing aromatic rings , one of the electron pairs of the heteroatoms contributes to the aromatic system ( similar to the non-basic nitrogen-containing rings ) , whereas the second lone pair extends in the plane of the ring ( similar to the primary nitrogen-containing rings ) .
In the oxygen- and sulfur-containing aromatic rings , one of the electron pairs of the heteroatoms contributes to the aromatic system ( similar to the non-basic nitrogen-containing rings ) .