卷扬机卷筒秘钢丝直径的比值应不汪于50。

根据《国务院关于投融资体制改革的决定》，对于企业不使用政府资金投资建设的项目，政府不再进行投资决策性质的审批，企业不需要编制( )。

A．项目可行性研究报告
B．设计文件
C．项目建议书
D．中长期发展建设规划

分子式为C₃H₆Cl₂的有机物发生一元氯代反应后，可生成2种同分异构体，则分子式为 C₃H₆Cl₂的有机物应是（　　）

A．1，3-二氯丙烷

B．1，1-二氯丙烷

C．1，2-二氯丙烷

D．2，2-二氯丙烷

信息导航法律服务产品功能包含哪些服务？（）

A.专业法律咨询服务

B.即时法律信息服务

C.自助法律服务

D.文档审核服务

E.案件委托服务

Although there are many skillful Braille readers, thousands of other blind people find it difficult to learn that system. They are thereby shut (1) from the world of books and newspapers, having to (2) on friends to read aloud to them.

A young scientist named Raymond Kurzweil has now designed a computer which is a major (3) in providing aid to the (4) .His machine, Cyclops, has a camera that (5) any page, interprets the print into sounds, and then delivers them orally in a robot-like (6) through a speaker. By pressing the appropriate buttons (7) Cyclops’s keyboard, a blind person can "read" any (8) document in the English language.

This remarkable invention represents a tremendous (9) forward in the education of the handicapped. At present, Cyclops costs $ 50,000. (10) , Mr. Kurzweil and his associates are preparing a smaller (11) improved version that will sell (12) less than half that price. Within a few years, Kurzweil (13) the price range will be low enough for every school and library to (14) one. Michael Hingson, Director of the National Federation for the Blind, hopes that (15) will be able to buy home (16) of Cyclops for the price of a good television set.

Mr. Hingson’s organization purchased five machines and is now testing them in Maryland, Colorado, Iowa, California, and New York. Blind people have been (17) in those tests, making lots of (18) suggestions to the engineers who helped to produce Cyclops.

"This is the first time that blind people have ever done individual studies (19) a product was put on the market," Hingson said. "Most manufacturers believed that having the blind help the blind was like telling disabled people to teach other disabled people. In that (20) , the manufacturers have been the blind ones.

8（）

A.visual

B.printed

C.virtual

D.spoken

如何避免眼睛疲劳？