阅读理解。 Sales of laptop computers passed

题目：

阅读理解。

     Sales of laptop computers passed desktops (台式电脑) in the US for the first time ever this fall, according

to market research firm IDC.

     That' s bad news for backs, necks and shoulders.

     "Laptops are basically not designed based on human bodies-unless you' re 2 feet tall," says physician

Norman J. Marcus, a muscle (肌肉 ) specialist in New York City.

     When you work at a computer, the keyboard should be at elbow height, so your upper and lower arms

form an angle (角度) of 90 degrees or more. The monitor (显示器) should be at about eye level so you can

rest back in a chair with back support.

     But most users simply set their laptops on a desk or table. The keyboard is too high, which makes your

arms reach up, your shoulders rise and your wrists (手腕) bend down. The monitor is too low, which pulls

your head and neck forward and down and this may hurt your back.

     That' s OK if you use your laptop occasionally, for short periods. But if you use one for hours without

stopping-as do millions of college students, business travelers, video-gamers and growing numbers of office

workers-you' re setting yourself up for muscle problems that can make your entire upper body hurt.

      Experts have warned about laptop problems for years-but without success. People continue to abandon

large and heavy desktops in favor of the smaller and lighter laptops. And WiFi (无线局域网 ) connections let

us use laptops anywhere-in bed, on the floor-and in all kinds of positions.

1. What Norman J. Marcus says in Paragraph 3 means _____ .

A. laptops are so badly designed

B. muscle pains are mainly caused by laptops

C. laptops are not suitable for people of usual height

D. laptops cause a lot of diseases easily

2. It can be known from the passage that ______.

A. we had better not use laptops too frequently

B. there are no suitable places for laptops

C. we shall buy desktops instead of laptops

D. desktops will face a hard future

3. Which of the following statements can be learned from the passage?

A. Using laptops doesn' t do harm to people' s health.

B. People pay little attention to the risks of laptop use.

C. Most people use laptops more often than desktops.

D. Laptops bring people more disadvantages than advantages.

4. The main purpose of the passage is to _____ .

A. show that laptops are widely used in the US

B. tell us people prefer laptops to desktops

C. persuade people not to use laptops any more

D. warn people of health problems caused by laptops