科学研究表明,平均每人约有20万根头发。头发的生长速度一般为3天1毫米,每月约增长1厘米。头发一般只有0.05毫米粗,人每天落发50～100根,每年大约要掉3.5万根。头发的同等截面承受力为钢的1.25倍。有人试验,用发辫能拉动一辆卡车。英国广播公司一次“创纪录”节目中,潘蒂兰小姐的一根头发竟承受了177.18克拉力。人发拉断前可延展20～30％。上述性能都是其它纤 Scientific research shows that on average, there are about 200,000 hairs each. The growth rate of hair is generally 3 days 1 mm, an increase of about 1 cm per month. Hair is generally only 0.05 mm thick, 50 to 100 people hair loss per day, about 35,000 off each year. Equivalent section of the hair bearing capacity of 1.25 times the steel. Some people experiment, with braids can pull a truck. In a BBC record-breaking program, one of Miss Panditlan’s hair was 177.18 karats. People can be stretched before pulling off 20 to 30%. The above properties are other fibers