鱼雁yu yan

fish and wild geese—letters

• operand
• operant
• opera seria
• operation
• operative
• operetta
• operon
• ophicleide
• ophir
• ophite
• ophites
• ophryon
• ophthalmia neonatorum
• ophthalmology
• ophuls，max
• opie，john
• opinion
• opinioned
• opitz，martin
• opium
• opium poppy
• opole
• oporto(或porto)
• opossum
• oppenheimer