Please someone correct my english - Thanks

Thank you, although I am not the person posted the original post.

Two questions:

1. In regard to your correction, can we put the article/determiner "the" in front of the words "copies"?

2. Why is that after the phrase "most of the invoices" the verb is in singular and in the following sentence the verb is in the plural form?

All of the rooms have private baths, and most have radios and TV.

Also, why not "TVs"? The word "TV" cannot be in a plural form?   

3. I said, "Thank you, although I am not the person posted the original post" and my question is does the conjunction "although" alway ask for a comma right before it? Can you think of an incidence/situation where it is not needed? 

Thank you.

Congratulations on you reaching the 5000 mark.

I was looking at your original response "... so please send copies of the following ones so we ..."  and somewhat understood why the determiner might not be needed.

Please tell me why one would need and the other would not.

1. please send copies of the following ones (general reference?)

2. please send the copies of the ones listed in the following list.  (specific reference?)

Would you say the concept of looking at the subsequent defining or identifying clause/phrase to decide whether to put a determiner "the" is predicated on the fact that the person who is writing/reading the sentence is able to see the whole context involved? Having a cursory look at the phrase "copies of the following ones," a person might be inclined to put the determiner "the," but after looking at the whole sentence and the context of the phrase that is in existence, then that person would be more apt to do without the determiner "the." Right?