问答题

Practice 2　　The laptop computer is a small, portable computer that’s light and small enough to hold on your lap. It is smaller than a luggage but larger than a notebook computer. A laptop usually weighs between 8 and 14 pounds, and when folded shut is about the size of a small briefcase. Laptops can be plugged in or run on batteries, although the batteries must be recharged every few hours. Laptop computers use a thin, light weight display screen called a flat-panel display, rather than the cathode ray tube technology of larger personal computers. Laptop displays vary widely in quality. Typically, their display screens show fewer lines than displays on larger computers and can be difficult to read in bright light. Laptops are self-contained units, having their own CPUs, memory, and disk drives. While more expensive than a desktop computer with equivalent computing power, a laptop can be ideal for the on-the-go user who needs a second, portable computer. Laptops aren’t always a suitable replacement for desktop computer, since they can’t be expanded or modified easily should your computing needs change. Also, the display is inferior to standard video graphics array（VGA）displays, although active matrix displays compete well except for size.