message blank造句

Finances were shaky, and most of the income came from sales of booklets, maps and message blanks.
Upon hearing the prosign the operator stops writing down or recording the current message text and prepares a new page ( or a new message blank from a pad of ARRL Radiogram blanks ) or just spaces down several lines to a new part of the page in preparation to copy a subsequent message.
It's difficult to find message blank in a sentence. 用message blank造句挺难的