Its main function is to transport something for completing the transport system....
There are four main groups of organic molecules<span> that combine to build cells and their parts: carbohydrates, proteins, lipids, and nucleic acids. So it would be C. Lipids</span>
<span>Two characteristics of leisure travelers is that they often will travel by car, and generally they take shorter trips. The whole idea of leisure travel is to take a little vacation from the chores of everyday life. It is generally characterized as people staying in nice hotels, relaxing, touring, and experiencing something new, fun and exciting.</span>
