n. 鸟嘌呤[化] 鸟嘌呤; 2-氨基-6-羟嘌呤
n. a purine base found in DNA and RNA; pairs with cytosine
1.That's assuming cytosine and guanine or thymine and adenine.
那你是假设了这些是胞嘧啶 鸟嘌呤 胸腺嘧啶和腺嘌呤