求翻译：随着汽车、机械、石油等工业的发展，铸件大型化已成为必然趋势。大型铸件的重量不单是几吨、几十吨的重量，而是达到了几百吨。例如，长江三峡水轮机仅叶轮就重达426t。是什么意思？

With the development of automobiles, machinery, oil industry, large castings has become an inevitable trend. The weight of the large cast is not just a few tons, dozens of tons of weight, but hundreds of tons. For example, only the impeller of the Yangtze River Three Gorges hydraulic turbine weighs

As automobiles, machinery, petroleum, industrial development, which has become a large casting an inevitable trend. The large casting weight is not only several tons, 10 tons of weight, but to a few 100 tons. For example, the Yangtze River Three Gorges Water turbine impeller is only up to 426 t.

Along with industry and so on automobile, machinery, petroleum development, the casting large scale has become the inevitable trend.Not merely the heavy casting weight is several tons, several dozens ton weights, but has amounted to several hundred tons.For example, the Three Gorges of the Yangtze R

With the development of industries such as cars, machinery, petroleum, enlargement has become an inevitable trend of casting. Not only the weight of several tons of large castings, dozens of tons of weight, but up to hundreds of tons. For example, the three gorges hydraulic turbine blade only weighs

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