how do i reword this sentence to a 9th grade leverl.

students know that charged particles are sources of electric fields and are subject to the forces of the electric fields from other charges.

It looks and sounds ok to me for the 9th grade. You might want to add a sentence giving an example.

Dutch folk dance are the usual dances that were (sang, danced, acted, etc., in front of people) by the folk. Foreigners and the Dutch alike, business partner Dutch folk dance with clog dancing, though clogs in practice limit the dance moves. ... (in the past) the Dutch danced in shoes as this was part of their Church going clothing.

To reword the sentence to a 9th-grade level, you can try the following:

"Students understand that charged particles create electric fields and can be influenced by the electric forces produced by other charges."

To simplify the sentence, I replaced the word "sources" with "create," since it better aligns with a 9th-grade vocabulary level. Additionally, I modified the phrase "are subject to" to "can be influenced by," making it more straightforward while conveying the same idea.