Co.

英文解釋：

名詞 co.:

1. an odorless very poisonous gas that is a product of incomplete combustion of carbon
   同義詞：carbon monoxide, carbon monoxide gas, CO
2. a hard ferromagnetic silver-white bivalent or trivalent metallic element; a trace element in plant and animal nutrition
   同義詞：cobalt, Co, atomic number 27
3. one who refuses to serve in the armed forces on grounds of conscience
   同義詞：conscientious objector, CO
4. a state in west central United States in the Rocky Mountains
   同義詞：Colorado, Centennial State, CO