A rat or pigeon might not be the obvious choice to tend to someone who is sick, but these creatures have some 26 superior skills that could help the treatment of human diseases.
2017年12月四级真题(第一套)阅读 Section A
英语六级真题
Some, like homing pigeons can be trained to deliver messages and packages.
出自-2016年12月听力原文
柯林斯高阶英汉双解学习词典释义
N-COUNT
鸽子
A pigeon is a bird, usually grey in colour, which has a fat body. Pigeons often live in towns.