蚕丝纤维因蚕的食性不同分成多种，其中有食桑叶形成的桑蚕丝纤维、食柞树叶形成的柞蚕丝纤维以及食木薯叶、马桑叶、蓖麻叶形成的其他野蚕丝纤维。桑蚕丝纤维和柞蚕丝纤维可以把长丝纤维的形态保留到集束形成的长丝纱中，其他的几种野蚕丝纤维只能被改形为短纤维用纺织加工。在用桑蚕丝纤维和柞蚕丝纤维集束形成的长丝纱中，桑蚕丝纤维的长丝纱最重要，占天然长丝纱的大部分。
简短的介绍中国丝绸的英语句子,加中文翻译
在古代，丝绸就是蚕丝（以桑蚕丝为主，也包括少量的柞蚕丝和木薯蚕丝）织造的纺织品。现代由于纺织品原料的扩展，凡是经线采用了人造或天然长丝纤维织造的纺织品，都可以称为广义的丝绸。而纯桑蚕丝所织造的丝绸，又特别称为“真丝绸”。
In ancient times, silk was a textile made of silk (mainly mulberry silk, including a small amount of tussah silk and cassava silk). In modern times, due to the expansion of textile raw materials, any textile woven with artificial or natural filament fibers can be called silk in a broad sense. The silk woven by pure mulberry silk is especially called "real silk".
丝绸
丝绸所含的天然纤维主要是蚕丝纤维，是熟蚕结茧时所分泌丝液凝固而成的连续长纤维，也称天然丝，是人类利用最早的动物纤维之一，包括桑蚕丝、柞蚕丝、蓖麻蚕丝、木薯蚕丝等。
唯一得到实际应用的天然长丝纤维，由蚕改粘液凝固而成。蚕丝纤维因蚕的食性不同分成多种，其中有食桑叶形成的桑蚕丝纤维、食柞树叶形成的柞蚕丝纤维以及食木薯叶、马桑叶、蓖麻叶形成的其他野蚕丝纤维。
桑蚕丝纤维和柞蚕丝纤维可以把长丝纤维的形态保留到集束形成的长丝纱中，其他的几种野蚕丝纤维只能被改形为短纤维用纺织加工。在用桑蚕丝纤维和柞蚕丝纤维集束形成的长丝纱中，桑蚕丝纤维的长丝纱最重要，占天然长丝纱的大部分。
用3到5个英语句子描述一下肥城跟西安的地点，特产，旅游胜地 求英语大神
Xi'an is the capital of Shaanxi province.It is the starting point of the Silk Road and famous for the Terracotta Army of Emperor Qin Shi Huang.
Xi'an has many areas that are easily accessible on foot. In many commercial, residential, educations zones in the city, especially in the shopping and entertainment districts around the Bell Tower, underpasses and overpasses have been built for the safety and convenience of pedestrians.
Besides many historical attractions in Xian, Xian is also a culinary city with much palatable Xian food. The most famous Xian food ranges from Pita Bread Soaked in Lamb Soup, Sheep Blood Soaked in Vermicelli Soup, Pork Sandwiched Between Pita Bread, to Cold Noodles and Qishan Noodles. These savory Xian cuisines are all must-eat along your Xian travel.
怎么用英语描写各国特产
Italy is famuos for noodles.Switzerland is famous for watch.
Germany is well-known for industry.
Indian is famous for IT.
Japenese is famous for fish.