题目

I wonder what it feels like to be one of______really rich. The Jenkinsons already have two Rolls Royces and now they are buying ____ third! A.the; a        B.the;the        C./;a           D./;the   答案：A“the十形容词”表一类人或一类事物，the rich富人；a third又一。组成核酸分子的碱基种类共有 [　　] A．2种B．4种 C．5种D．8种