◎ 题干
This kind of CD-ROM is very popular. Why not buy one before it___________?
A. comes out        B is come out       C. is sold out      D. sells out
◎ 答案
查看答案
◎ 解析
查看解析
◎ 知识点
    根据n多题专家分析,试题“This kind of CD-ROM is very popular. Why not buy one before it___________?A. comes out B is come out C. is sold out D. sells out…”主要考查了你对  【实义动词的单数第三人称形式】【实义动词】【动词短语】  等知识点的理解和应用能力。关于这些知识点的“档案”,你可以点击相应的链接进行查看和学习。