在中国，水稻生产是国民经济的重要组成部分。中国人早在公元前4000年就开始了水稻种植，而后逐渐传播到世界各地。目前，中国是世界上最大的水稻生产国，水稻产量占世界产量的26%。我国水稻主要种植于长江(the Yangtze River)沿岸及南方各省份。米饭是中国人，特别是南方人，非常重要的主食(staple food)。此外，水相还可以用来酿酒、制糖及用作工业原料。
参考译文：
China,rice production is an important part of the national economy. As early as 4,000 B.C.，the Chinese started rice cultivation which later gradually spread all over the world.At present, China is the world's largest producer of rice,producing 26% of the world rice output.The rice crop in China grows primarily in provinces along the Yangtze River and In the South.Rice is an important staple food for Chinese, particularly the southerners.In addition, rice can be used to make wine and sugar and used as industrial materials.
解析：
1.第2句中的“早在公元4000年”可用短语as early as 4000 B.C.来表达，置于句首。“而后逐渐传播到世界各地”处理为定语从句、修饰“水稻种植”、译作which later gradually spread all over the world，同时应将“水稻种植”译为名词形式rice cultivation。
2.第3句“中国世界上最大的......，水稻产量占......”可译为并列结构China is the world's largest... and its rice production accounts for...，但不如将后半句处理成伴随状语，用分词短语表达为producing 26% of world rice output更简洁、更有逻辑性。
3.第4句中的“我国水稻主要种植于……”如逐字对译为The rice in China is plant...则稍显生硬。宜用主动语态译出，表达为The rice crop in China grows primarily in...，此处增译crop(农作物)表达更精准。 地点状语“长江沿岸及南方”表达为along the Yangtze River and in the South，置于句末。
4.倒数第2句的主干是“米饭是非常重要的主食”。“中国人”用介词短语for Chinese译出，置于表语staple food之后。“特别是南方人”用particularly the southerners来表达，作“中国人”的同位语,置于句末。
