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求纺织专业英语文章,描写棉花的各种特性500字(英语文章)

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求纺织专业英语文章,描写棉花的各种特性500字(英语文章)
Description and technical features
Cotton is a natural fibre of vegetable origin, like linen, jute or hemp. Mostly composed of cellulose (a carbohydrate plant substance) and formed by twisted, ribbon-like shaped fibres, cotton is the fruit of a shrubby plant commonly referred to as the "cotton plant". The cotton plant, a variety of plants of the genus Gossypium, belongs to the Malvacae family, which comprises approximately 1,500 species, also including the baobab tree, the bombax or the mallow. The plant, growing up to 10 metres high in the wild, has been domesticated to range between 1 to 2 metres under commercial cultivation. Either herbaceous or ligneous, it thrives in dry tropical and subtropical areas. Whereas by nature the plant is a perennial tree (lasting about 10 years), under extensive cultivation it is mostly grown as an annual shrub. The cotton flower has five large petals (showy, white, white-creamy, or even rose in colour), which soon fall off, leaving capsules, or "cotton bolls", having a tick and rigid external layer. The capsule bursts open upon maturity, revealing the seeds and masses of white/creamy and downy fibres. Cotton fibres of the Gossypium hirsutum species range from about 2 to 3 centimetres in length, whereas Gossypium barbadense cotton produces long-staple fibres up to 5 centimetres length. Their surface is finely indented, and they become kinked together and interlocked. The cotton plant is almost exclusively cultivated for its oleaginous seeds and for the seminal fibres growing from them (i.e. cotton, strictly speaking). In ordinary usage, the term "cotton" also makes reference to fibres that are made into fabric wires suitable for use in the textile industry.
Although the cotton plant is native to tropical countries, cotton production is not limited to the tropics. Indeed, the emergence of new varieties, as well as advances in cultivation techniques led to the exapansion of its culture within an area straddling from approximately 47 degrees North latitude (Ukraine) to 32 degrees South (Australia). Although cotton is widely planted in both hemispheres, it remains a sun-loving plant highly vulnerable to freezing temperatures. Cotton is crucially important to several developing countries. Out of the 85 cotton-producing countries in 2005, 80 were developing countries, 28 of which were indexed by the United Nations among the least developed countries (LDCs).