In connective tissue, the role of elastic fibers is to

The role of elastic fiber is to keep the tissue length(or elasticity). That means if the tissue is stretched the elastic fiber will exert force to make it back into the normal length. This fiber can be found in skin and lack of it will make wrinkle. Other connective tissue would be collagen which will give strength

B) raising the temperature and reducing the volume of the gas.|-/ 

This is the answer: body 1 + engine 2