在麻醉前用药中，能引起顺行性遗忘的药物是（）。 A.异丙嗪 B.咪达唑仑 C.戊巴比

为了了解某地区初一年级5000名学生的体重情况，从中抽取了450名学生的体重，就这个问题来说，下面说法中正确的是[ ]

A．样本容量是450

B．每个学生是个体

C．450名学生是所抽取的一个样本

D．5000名学生是总体

美国一项最新研究报告说，利用基因技术对免疫细胞进行改造后可以使它们更有效地杀灭癌症细胞，这种方法已被成功应用于治疗白血病，研究人员认为它对其他癌症可能同样有效。上述材料蕴涵的哲理是

①实践与认识的辩证关系   ②运动与静止的辩证关系

③共性与个性的辩证关系   ④肯定与否定的辩证关系

A．①③

B．②③

C．①④

D．②④

阅读理解

     Looking back on my childhood, I am convinced that naturalists are born and not made.Although we

were all brought up in the same way, my brothers and sisters soon abandoned their pressed flowers and

insects.Unlike them, I had no ear for music and languages.I was not an early reader and I could not do

mental arithmetic.

     Before World War ? we spent our summer holidays in Hungary.I have only the dim memory of the

house we lived in, of my room and my toys.Nor do I recall clearly the large family of grandparents, aunts,

uncles and cousins who gathered next door.But I do have a clear memory of the dogs, the farm animals,

the local birds, and above all, the insects.

     I am a naturalist, not a scientist.I have a strong love of the natural world and my enthusiasm led me

into varied investigations.I love discussing my favorite topics and enjoy burning the midnight oil while

reading about other people's observations and discoveries.Then something happens that brings these

observations together in my conscious mind.

     Suddenly you fancy you see the answer to the riddle, because it all seems to fit together.This has

resulted in my publishing 300 papers and books, which some might honor with the title of scientific

research.

     But curiosity, a keen eye, a good memory and enjoyment of the animal and plant world do not make

a scientist:one of the outstanding and essential qualities required is selfdiscipline, a quality I lack.A

scientist requires not only selfdiscipline, but hard training, determination and a goal.A scientist, up to a

certain point, can be made.A naturalist is born.If you can combine the two, you get the best of both

worlds.

1. The first paragraph tells us the author________.

A. was interested in flowers and insects in his childhood

B. lost his hearing when he was a child

C. didn't like his brothers and sisters

D. was born to a naturalist's family

2. The author can't remember his relatives clearly because________.

A. he didn't live very long with them

B. the family was extremely large

C. he was too young when he lived with them

D. he was fully occupied with observing nature

3. Which of the following statements is TRUE according to the passage?

A. The author is a naturalist, but not a scientist.

B. The author is a scientist as well as a naturalist.

C. The author is first of all a scientist.

D. The author is neither a naturalist nor a scientist.

4. The author says that he is a naturalist rather than a scientist probably because he thinks he________.

A. has a great deal of trouble doing mental arithmetic

B. lacks some of the qualities required of a scientist

C. just reads about other people's observations and discoveries

D. comes up with solutions in a most natural way

由于自然地理环境的各个因素(气候、地形、土壤、水陆分布、资源贮存等)在地球表面的分布表现巨大地理差异性，因而各种因素在某一地区的不同组合对人口分布所提供的条件就大不一样。现在世界上人口分布的不平衡，在很大程度上是由于自然地理条件所施加的种种影响造成的。
　　这段话支持了这样一个论点，即( )。

A．自然地理环境因素在各地区表现有诸多差异性

B．自然地理环境的差异因素是人口分布不平衡的决定因素

C．世界人口的分布不平衡皆因自然地理环境之差异

D．自然地理环境的差异影响着各地的人口分布状况

在生产上，小麦的最佳收获时期的特征为（）。

A.上部叶片、叶鞘变黄，但未干枯

B.80%以上的籽粒背复面全呈黄色

C.胚乳稠蜡状，用指甲可压扁，但已无浆液

D.以上均正确