Kemgbe ọbịbịa nke carbide cimented na 1923, ndị mmadụ na-aga n'ihu na-ebuli akụrụngwa ya kachasị site n'ịkwalite usoro nhazi ya, na-akwadebe ntụ ntụ mejupụtara WC-Co nke ọma, yana ike elu.Otú ọ dị, n'ihi nsogbu nke ngwá ọrụ dị mgbagwoju anya, ọnụ ahịa nkwadebe dị elu, na nnukwu te ...
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