系统解析:1.翻译第一句时,为了增加句式多样性,可以将“平均海拔3000米以上”翻译为with引导的介词短语。“大部分地区为高山和高原”既可以像参考译文那样处理为and连接的并列句,也可以处理为定语从句,与第一个分句合并翻译,译为“With an average altitude of more than 3000 meters, Qinghai is a province in northwestern China which is dominated by high mountains and plateaus.”。
2.第二句中“全国最大的咸水湖”用来修饰“青海湖”,可以像参考译文那样,翻译为Qinghai Lake的同位语,也可以处理为定语从句,即“The province is named after Qinghai Lake, which is the largest saltwater lake in China.”。
3.第三句中的三个分句为并列成分,可以像参考译文那样,将第一个分句处理为分词结构,将后两个分句译为and连接的句子,还可以将第一个分句翻译为主句,将后两个分句处理为定语从句,即“Qinghai Lake is known as the most beautiful lake in China, which is one of the most popular tourist attractions and the heaven for photographers and artists.”。
4.第四句比较长,可以按照中文的意群进行适当的划分,译为两句。可以将前三个介绍青海自然资源的分句合并翻译,将“省内许多城市的经济……发展”单独成句。翻译后半部分时,可以像参考译文那样以“石油和天然气工业”为主语,也可以以“省内许多城市的经济”为主语,使用被动句式,即“The economy of many cities within the province has been greatly developed under the impetus of the oil and natural gas industry.”。
5.翻译第五句时,可以像参考译文那样,将第一个分句译为一句,将后两个分句合并翻译,也可以将第一个分句译为主句,第二个分句译为定语从句,第三个分句译为结果状语从句,即“Qinghai is especially renowned for its rich water resources, which serves as the source of China's three major rivers, namely the Yangtze River, the Yellow River and the Lancang River, thus playing a vital role in China's water ecosystem.”。