我是一名园艺教育专业的专科生，面对就业形势，我...

简述遗忘的基本规律?

用洛必达法则求极限：

Passage Two
The thought of not sleeping for twenty-four hours or more is not a pleasant one for most people．The amount of sleep that each person needs varies．In general,each of us needs about eight hours of sleep each day to keep our bodies healthy and happy．Some people,however,can get by just a few hours of sleep at night．
It doesn't matter when or how much a person sleeps．But everyone needs some rest to stay alive．Few doctors would have thought that there might be an exception on this．Sleep is,after all,a very basic need．But a man named AI Herpin turned out to be a real exception,for supposedly,he never slept!
A1 Herpin was 90 years old when doctors came to his home in New Jersey．They hoped to negate the claims that he never slept．But they were surprised．Though they watched him every hour of the day,they never saw Herpin sleeping．He did not even own a bed．He never needed one．
The closest that Herpin came to resting was to sit in a rocking chair and read a half dozen news-papers．His doctors were baffled by this strange case of permanent insomnia．Herpin offered the only clue to his condition．He remembered some talk about his mother having been injured several days be-fore he had been born．Herpin died at the age of 94,never having slept a wink．

The most likely reason on Herpion's insomnia was______

A.his mother's injury before he was born
B.that he never got tired
C.his magnificent physical condition
D.that he got enough rest rocking

肩关节脱位常发生在（　　）

A.前上方

B.后上方

C.上方

D.后下方

E.前下方