Kev taw qhia los ntawm Ministry of Natural Resources ntawm Tuam Tshoj thiab Tianjin Municipal People's Government, tuav los ntawm Tuam Tshoj Mining Federation, thiab ua los ntawm Tianjin Mining Expo International Exhibition Co., Ltd., 2021 (nees nkaum peb) Tuam Tshoj International Mining Conference wb...
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