【答案解析】In the late Spring and Autumn Period in the 5th century B. C., a canal was first cut near Yangzhou, Jiangsu, to guide the waters of the Yangtze River to the north. This was lengthened first during the Sui Dynasty of the 7th century, and finally during the Yuan Dynasty of 13th century, to become what has been known as the Grand Canal. The Grand Canal was the major transport artery between north and south China during the Yuan, Ming and Qing Dynasties, contributing greatly to the economic and cultural exchange between north and south. Owing to the development of the maritime transport between north and south and the opening of the Tianjin-Pukou and Beijing-Hankou railways after the mid-19th century, the role of the Grand Canal was greatly reduced and many sections of it fell into disrepair or became choked with mud. The Grand Canal gained a new lease on life after the founding of the People"s Republic of China. Except for the section in Shandong which is only partly serviceable, many other sections are navigable in some of the seasons while the 800-kilometer stretch from Jiangsu to Zhejiang open to year-round shipping. [解析] 在公元前5世纪春秋末期，首先在江苏扬州附近开凿了一条运河，把长江的水引向北面。
这句话中并没有出现动词“开凿”的动作施动者，翻译时需要将运河(canal)提为主语，然后使用英文的被动语态。
In the late Spring and Autumn Period in the 5th century B.C., a canal was first cut near Yangzhou, Jiangsu, to guide the waters of the Yangtze River to the north.
这条运河最初在公元7世纪隋朝时期得到扩长，最后在公元13世纪被修成了今天的大运河。
参考译文将公元13世纪的“元朝”这一信息补充出来，元朝成吉思汗统一蒙古高原，进行西征，丝绸贸易得到进一步发展，中西交流空前繁荣，因此在西方的历史记载中有关元朝的信息想必较为常见，因此加上这一信息，有助于译文读者阅读理解。
This was lengthened first during the Sui Dynasty of the 7th century, and finally during the Yuan Dynasty of 13th century, to become what has been known as the Grand Canal.
在新中国成立后，大运河又焕发了生机。
“a new lease on life”有“重获新生”的意思，这里“焕发了生机”是“在其一度荒废之后有了新的生机”的含义，因此使用这个表达非常恰当。
The Grand Canal gained a new lease on life after the founding of the People"s Republic of China.
除山东地段只能部分通航之外，大运河很多其他的地段在一些季节能通航，从江苏至浙江的800千米地段能全年通航。
“能够通航”的对应英文为“navigable”，前边的“serviceable”表示可以使用，放在这样的语境中也可以表达“可通航”的含义，同时也避免了用词上的重复；“全年”为“year-round”。
Except for the section in Shandong which is only partly serviceable, many other sections are navigable in some of the seasons while the 800-kilometer stretch from Jiangsu to Zhejiang open to year-round shipping.