Matching sediment patterns in the fragments with those in the hollow niches where the Buddhas once stood offers key clues to the pieces' original position.
通过将残片的泥沙类型与佛龛上的黏土类型进行配比，为碎片原来所处的位置提供了重要线索。
2
The key ingredient in the recipe is carbon nanotubes — submicroscopic hollow tubes made of a chicken-wire-like lattice of carbon atoms.
这个实验中的关键部件是碳纳米管，即一种由类似铁丝织网一样的碳原子网格组成的亚微观中空管。
3
Hollow cathodes are key assemblies of reliability and life for an electric propulsion system, and their developments are strongly depended on a series of tests.