The structure of a star can often be thought of as a series of thin nested shells, somewhat like an onion.

恒星的结构经常被想象成一系列套在一起的薄层，就像洋葱一样。

Then he introduced his two star witnesses-the two tiny shells found alongside the body of maude Bauer.

然后他引进了他的两个最主要的证人——在莫德·波尔尸体旁边找到的两颗小弹壳。