Friction creates heat between two objects rubbing together, and slows the moving object down.
A long carbon and hydrogen chain and a carboxyl group.
In images of fatty acids (the monomers of Lipids), it is depicted as a long carbon chain with hydrogen on the ends and connected to them as well, yet on the clear side is the carboxyl group.
Hope this helps!
TRNA and mRNA i would say
Th answer is D its the best answer that fits the question .