生态系统是按照（）组织起来的基于生态系统承载力、具有高效的经济过程及和谐的生态功能的

长骨干骨折的临床愈合一般需要（）。

A.3周

B.4周

C.5周

D.6周

E.8～12周

请用不超过200字的篇幅，概括出给定资料所反映的主要问题。
要求：概括全面，层次分明，条理清楚，表述简洁。

男孩，7岁。1周前开始发热，全身不适，食欲下降，大便干结，轻度腹胀，近2d轻咳，无痰。体检：体温38.9℃，神志清，软弱，心脏无异常，两肺呼吸音略粗，无啰音，肝肋下2cm，脾肋下1.5cm，软，无压痛。血象；白细胞数4.6×10⁹/L，中性粒细胞0.68，嗜酸性粒细胞计数为O。肥达反应：O效价1:40，H效价1:80，胸部X线透视正常。

[假设信息]假如患儿住院治疗10d，完全恢复出院。出院半个月后又开始发热，体温38.2～39.4℃，持续8d，食欲下降，腹胀，腹泻，大便每天2～3次，稀，无脓血。体检：肝肋下2cm，脾肋下3cm。血象白细胞计数5.4×10⁹/L，中性粒细胞0.80。血培养有伤寒杆菌生长。该病人的诊断是

A．伤寒反复感染

B．伤寒复燃

C．伤寒复发

D．伤寒迁延型

E．伤寒合并肝炎

与“寒从中生”关系最密切的是

A．脾

B．肾

C．肺

D．肝

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