Bọọlụ nchara na-ebu nwere ọtụtụ ọkwa.Dị ka ọkwa ndepụta na mba ọkọlọtọ GB/T308-2002, ha na-ekewa n'ime G5, G10, G16, G28, G40, G60, G100, G200, G500, G1000, wdg G bụ akwụkwọ ozi mbụ nke Grade na English. , na ọnụọgụgụ ndị a nwere ọkwa dị iche iche.Nke nta nke nta ahụ ...
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