A shade is produced by adding black to some base shade, expanding its darkness. Shades appear a lot more remarkable and richer.K?t Qu? X? S? K?t Qu? X? S? Mi?n Nam K?t Qu? X? S? Mi?n Trung K?t Qu? X? S? Mi?n B?c KQXS Các T?nh KQXS ?i?n Toán X? s? ?i?n toán Mega six/forty five X? s? ?i?n toán Electric power six/fifty five X? s? ?i?n toán Max3D