作为计算机的核心部件，运算器对信息进行加工、运算。运算器的速度决定了计算机的计算速度，它一般包括______。 Ⅰ．算术逻辑运算单元 Ⅱ．一些控制门 Ⅲ．专用寄存器 Ⅳ．通用寄存器

A．Ⅰ和Ⅱ

B．Ⅲ和Ⅳ

C．Ⅰ、Ⅲ和Ⅳ

D．全部

--- Steve is good at writing stories.

--- So he is. But he writes ____ than us. So he can get good grades in writing.

A．careful

B．more careful

C．carefully

D．more carefully