The answer is C.
The story says, "Then, gently put the valve of the tube through the hole in the rim and insert the rest of the tube into the tire, being careful not to twist it."
1. Since research papers are usually lengthy, a “table of contents” could help the reader navigate through the paper in an organized way.
2. Headings above each section could provide a simple, clearly defined format that works to break up the dense paper into distinct portions.
The letter m
It happens once is a Minute and twice in a MoMent but never in a lifetime.
