题目

下列说法中错误的是（    ） A．DNA上的一些具有特定遗传信息的片段叫基因 B．每种生物的细胞内，染色体的数量是一定的 C．细胞核是遗传信息库     D．染色体由DNA和核酸组成 答案：D Millions of pounds’ worth of damage ________ by a storm which swept across the north of England last night． [　　] A． had been caused B． has been caused C． will be caused D． will have been caused