小华学了声现象的知识后，总结出以下四点，其中你认为错误的是[ ] A．声音是靠物

He was going to put      some signs       old books.

A．up; asking to

B．up; to ask for

C．on; to ask to

D．down; asking for

In spite of ill health and a physical disability that threatened her career, Carson McCullers completed a novel in the summer of 1961 that made the best-seller list.

A．inability

B．incapacity

C．incapability

D．failure

在糖脂互变过程中，糖分解代谢的中间产物（）可以还原生成3-磷酸甘油

A、丙酮酸

B、PEP

C、乙酰CoA

D、磷酸二羟丙酮

最常见的阻生牙是（）

A.下颌第三磨牙

B.上颌第二磨牙

C.下颌第二前磨牙

D.上颌尖牙

E.上颌侧切牙

下列各存储器中，存取速度最快的是( )。

A．CD-ROM
B．内存储器
C．软盘
D．硬盘