【英语时差8,16】罕见的独角鲸-下

Males may use their tusks² in fights with other males to establish social hierarchies³. Tusks could also be used for breaking through thin layers of ice in their freezed ocean habitate.

 

Researchers from Harvard School of Dental Medicine think the giant tooth might also act as a sensory⁴ organ. With the electron microscope, they discoveried that the surfaces of narwhal's tusk¹ is covered with millions of tiny nerventings. These nerves connected to the narwhal's brain through a network of tiny tubes in the tooth.

 

The scientists believed that the narwhals used the sensitive tusks to detect changes in temperature, solt content, and flow patterns in the environment around them. But since only males grow tusks, it's likely that the tusks did not evolve primarily as a sensory organ, more researchers need to really understand why narwhals have tusks, and how they use them.

1 tusk   

n.獠牙，长牙，象牙

参考例句：

• The wild boar had its tusk sunk deeply into a tree and howled desperately.野猪的獠牙陷在了树里，绝望地嗥叫着。
• A huge tusk decorated the wall of his study.他书房的墙上装饰着一支巨大的象牙。

2 tusks   

n.（象等动物的）长牙( tusk的名词复数 )；獠牙；尖形物；尖头

参考例句：

• The elephants are poached for their tusks. 为获取象牙而偷猎大象。
• Elephant tusks, monkey tails and salt were used in some parts of Africa. 非洲的一些地区则使用象牙、猴尾和盐。 来自英语晨读30分（高一）

3 hierarchies   

等级制度( hierarchy的名词复数 )； 统治集团； 领导层； 层次体系

参考例句：

• That's a trip of two hierarchies. 那是两个领导层之间的互访。
• Hierarchies of authority, spans of control, long-range plans, and budgets. 等级森严的权力机构，控制范围，长期计划，预算。 来自英汉文学 - 廊桥遗梦

4 sensory   

adj.知觉的，感觉的，知觉器官的

参考例句：

• Human powers of sensory discrimination are limited.人类感官分辨能力有限。
• The sensory system may undergo long-term adaptation in alien environments.感觉系统对陌生的环境可能经过长时期才能适应。