dull luster

例句：

1. 1. The oldmirror had a dull luster that washard to see through.
   那面旧镜子的光泽很难看清。
2. 2. The new car's shiny exterior gave off a bright anddull luster.
   新车闪亮的外观发出明亮而暗淡的光泽。
3. 3. Thediamond's dull luster was hidden beneath the surfaceof the stone.
   钻石的暗淡光泽隐藏在石头的表面之下。