8 Cov Txheej Txheem Kev Luam Ntawv Zoo Tshaj Plaws Nws tuaj yeem ua haujlwm ntawm cov khoom tiaj tus, cov khoom kheej kheej, cov khoom nkhaus, thiab txawm tias concave thiab convex nto.Piv txwv li, khaub ncaws, ntoo, thiab lwm yam tuaj yeem luam tawm, nrog kev hloov pauv zoo.A...
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