Personal computers are used by one person at a time. The largest personal computer, or PCS, can fit on a (1) . Some of these (2) have more than one microprocessor. (3) the primary processor, which is a general-purpose device, a PC may have one or more processors to (4) special kinds of work. Some machines, (5) , have maths processors, others have graphics processors to help process photographs and other illustrations. Still others have (6) processors.
Office workers also use PCS that are not (7) to a network. These machines are used for (8) tasks as word processing, performing financial calculations, and organizing and (9) bodies of information called databases. People use PCS at (10) for some of the same kinds of tasks. They use word processing programs for (11) Communication, financial software for household budgets. Individuals also use their home computers to play (12) and to communicate (13) the internet.
Small, portable PCS are (14) with people who often work away from their desks. The (15) include laptop computers, which can be (16) on the lap; notebook computers, which are about the (17) of a loose leaf notebook; and palmtop, or handheld computers, which can be operated while (18) in the hand. Laptop and notebook computers have the same (19) as desktop computers. Palmtop computers have less power but still (20) some advanced capabilities. For example, they can process household financial data.
二、完形填空
A．processor
B．power
C．usage
D．palm
，垂直于PQ、MN，所在区域有竖直向下的磁感应强度为B的匀强磁场。竖直放置的两平行金属板A、B之间的距离是d，分别与Q、N连接。闭合开关S，ab在大小为F的水平外力作用下恰好处于静止状态，待电路稳定后，一质量为m、电荷量为q的正粒子从A、B的左端某位置以初速度v0水平射入板间，从右端飞出时速度大小是2v0。不计粒子重力。（R1、R2、R3不是已知物理量，R0是已知物理量）求： 