bracketed arithmetic expression

例句：

1. 1.The box was bracketed withmetal bands.
   这个盒子用金属带子包裹着。
2. 2. The painting is bracketed by a border of gold.
   这幅画被金色边框包围着。
3. 3. Thesculpture is bracketed by a stone archway.
   这座雕塑被一座石拱门包围着。