Special 13) wires are put across the brackets and then tightened with tiny 14) elastics .
Special 13) wires are put across the brackets and then tightened with tiny 14) elastics .
特殊的金属线穿过牙箍，再用细小的橡皮圈拉紧。
Special 13) wires are put across the brackets and then tightened with tiny 14) elastics .
特殊的金属线穿过牙箍，再用细小的橡皮圈拉紧。