求下文的英译汉2 不要机械翻译 谢谢
With 35 watchtowers over a stretch of only 5 ½ kilometers, the Simatai section of the Great Wall has probably the greatest number of watchtowers per kilometer than any other section of the Great Wall. Simatai Great Wall is divided into two subsections that lie on either side of a lake, Yuanyang Hu ("Mandarin Duck Lake"), which is fed by two springs, one hot and the other cold, with the result that the lake never freezes over even during the severest of winters. The subsection of the Simatai section that lies west of Mandarin Duck Lake snakes up a gently rounded mountain ridge. Here there are 20 watchtowers spread out at varying distances, in keeping with the dictates of the terrain and the need for supply depots/ added fortifications (which is the role played by the watchtowers).
To the east of the lake, the terrain changes character entirely, with a rugged mountain ridge that resembles the “razor” back of a wild boar. Here there are 15 watchtowers, most of them located on sheer precipices, and most of them situated at an altitude of above 1000 meters above sea level. The terrain to the east of the lake descends sharply, right down to the water's edge, with no shoreline to speak of.
Since both subsections of the Simatai section of the Great Wall descend from either side into the depression in which Mandarin Duck Lake is nestled, and since the snaking mountain ridges on either side of the lake are visible from the far end of the oblong lake, the macro view of the landscape, according to the vividly imaginative Chinese imagination, is one of two dragons leaping out of the lake, each in opposite directions.