Thank you for your responses. I sincerely appreciate them!
I have been working at this ebook for most of the day and solved the problem by moving "Part..." to the next line in the MS Word document. Now Calibre does not separate the chapter number from the chapter title. I do not know anything about code, but it seems that the word "part" is a flag that causes a page break. I wonder what you think...?
Attached are two screenshots from two chapters of the seven that are now corrected. Thank you! I sincerely appreciate them!