听力原文： From the earliest times, man has clothed himself in fabrics of one sort or another. At first, he depended upon animal skins and furs. Then he learned to make crude materials by interweaving flexible strands, such as vines and creepers, into primitive forms of cloth. This was the beginning of textile manufacture, which has now grown into one of world's great industries. The production of textile fabrics by an interweaving process was possible only if suitable strands were available. The stems of plants, and strips of animal skin, possessed the strength and flexibility that enabled them to be woven into coarse materials. As man became more civilized, he demanded finer fabrics for clothing and other purpose. In China, for example, wonderfully fine continuous filaments, or thin threads, were obtained by unwinding the cocoons of silk-worms. Flexible strands were made by combining several of these filaments together, and the strands of silk were woven into fabrics of the finest quality. Then China became famous for her silks, which were carried by traders to various parts of the world. (26)