"any of several fat-soluble vitamins essential for normal vision; prevents night blindness or inflammation or dryness of the eyes"
"the basic unit of electric current adopted under the Systeme International d'Unites"
"the 1st letter of the Roman alphabet"
"the blood group whose red cells carry the A antigen"
"a very poisonous metallic element that has three allotropic forms; arsenic and arsenic compounds are used as herbicides and insecticides and various alloys; found in arsenopyrite and orpiment and real"
"a United States territory on the eastern part of the island of Samoa"