Answer:(a) Only 1
Carbon fibers are used in the manufacture of components used in automobiles and aircraft: This statement is correct. Carbon fibers are lightweight and have high strength, making them ideal for applications in the automotive and aerospace industries. They are used to manufacture components such as body panels, structural parts, and interior components in automobiles and aircraft.
Carbon fibers once used cannot be recycled: This statement is incorrect. Carbon fibers can be recycled, although the process is more challenging compared to other materials. There are recycling methods available for carbon fibers, including mechanical recycling and chemical recycling, which can recover and reuse the carbon fibers in various applications.