Molecules that make up the rails of the dna structure? ?

DNA has a "sugar-phosphate back bone", this means that the DNA "rails" are made up of deoxyribose (a sugar) and phosphates. Ribose is the sugar component of RNA, and all the other things on that list are DNA/RNA bases.  hope this helps :)

Where is the rest of the question

It depends on the surface of the levels. the rougher the surface, the greater is the frictional force. for rougher surfaces, you would need to exert greater force to move the object. the concept is that, you must overcome the frictional force in order to bring the object into motion. this is the reason why we add lubricants to the joints so they could easily move. this answer was on