She explained to the maintenance people that all the other types of trees would grow very tall, the telephone wires, which are twenty-five feet up, would get tangled among the branches.

Comma splice

Explanation:

From the sentences, there are two independent clauses and these clauses are joined by a comma to make the full sentence. The first part of the sentence "She explained to the maintenance people that all the other types of trees would grow very tall" can stand alone, so can the second part of the sentence, but they are been joined by a comma to form one sentence.

the template that is used is page layout then the margins option and finally choose the normal option.