Ihe omuma nyocha nke igwe nchara nchara site na dayameta (DN 80-300, DN 350-600, DN 700-1000, DN 1200-2000 na DN2000 na n'elu), ngwa (mmiri, mmiri mkpofu na ogbugba mmiri n'ubi) na mpaghara (North America) , Europe, Asia-Pacific na ụwa ndị ọzọ) - ...
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