boxhead

例句：

1. 1. The scientist studied the structure of the human cranium.
   这位科学家研究了人类颅骨的结构。
2. 2. The skull was found in a cave with a broken sword.
   在洞穴里发现了一个破碎的剑，头骨在其中。
3. 3. The skull is an important part of the skeletal system.
   头骨是骨骼系统的重要组成部分。