在地球仪上，经线指示_________方向，南、北半球的分界线是________

男孩9岁，气喘半日，每年春秋季发病，体温36.5℃，两肺有普遍哮鸣音，白细胞7.6×10⁹/L，中性粒细胞0.76，诊断可能为（）

A.喘息性支气管炎

B.支气管哮喘

C.过敏性肺炎

D.急性支气管炎

E.支气管肺炎

双代号网络图的基本构成要素有( )。

A．箭线

B．圆圈

C．虚工作

D．编号

E．线路

阅读理解。

     Edward Wilson is America's, if not the world's, leading naturalist. In The Future of Life, he takes us

on a tour of the world's natural resources (资源). How are they used? What has been lost? What

remains and is it able to continue with the present speed of use? Wilson also points out the need to

understand fully the biodiversity (生物多样性) of our earth.

     Wilson begins with an open letter to the pioneer in environment (环境) protection, Henry David

Thoreau. He compares today's Walden Pond with that of Thoreau's day. Wilson will use such

comparisons for the rest of the book. The problem is clear: man has done great damage to his home

over the years. Can the earth, with human help, be made to return to biodiversity levels that will be able

to support us in the future?

     Biodiversity, Wilson argues, is the key to settling many problems the earth faces today. Even our

agricultural crops can gain advantages from it. A mere hundred species (物种) are the basis of our food

supply, of which but twenty carry the load. Wilson suggests changing this situation by looking into ten

thousand species that could be made use of, which will be a way to reduce the clearing of the natural

homes of plants and animals to enlarge farming areas.

     At the end of the book, Wilson discusses the importance of human values in considering the

environment. If you are to continue to live on the earth, you may well read and act on the ideas in this book.

1.We learn from the text that Wilson cares most about ______.

A. the environment for plants

B. the biodiversity of our earth

C. the waste of natural resources

D. the importance of human values

2. How many species are most important to our present food supply?

A. Twenty.  

B. Eighty.

C. One hundred.  

D. Ten thousand.

3.Wilson suggests that one way to keep biodiversity is to ______.

A. learn how to farm scientifically

B. build homes for some dying species

C. make it clear what to eat

D. use more species for food

4. We can infer that the text is ________.

A. a description of natural resources

B. a research report

C. a book review

D. an introduction to a scientist

牙髓感染最常见的途径是

A．牙隐裂
B．楔状缺损
C．深龋
D．牙外伤
E．磨耗

对流免疫电泳实质上是（）

A．定向加速度的免疫双扩散技术

B．单向电泳扩散免疫沉淀技术

C．区带电泳与免疫双扩散技术

D．双向加速度的电泳技术

E．区带电泳