避雷针的标注应表示避雷针在水平面上的保护半径、避雷针的（）高度。

在一个不透明的口袋里装有4个球，分别是红球2个，黄球1个，绿球1个，它们除颜色不同外其余都相同．闭上眼睛搅拌均匀后，第1次从袋中任意摸出1球（不放回），第2次再任意摸出1球，请你用画树状图或列表格的方法，求两次都摸到红球的概率．

冻疮症见神疲体倦，气短懒言，面色少华，创面不敛，创周暗红漫肿，舌淡苔白，脉细弱或虚大无力。此证属（）

A.寒凝血脉

B.寒凝血瘀

C.寒凝化热

D.寒盛阳衰

E.气虚血瘀

在面向对象方法中，实现信息隐蔽是依靠

A．对象的继承

B．对象的多态

C．对象的封装

D．对象的分类

阅读理解。

     In 2004, the World Health Organization, WHO, warned of a possible outbreak of another serious disease

which may be even more deadly than SARS. The WHO believes that it is likely that bird flu will spread to

human beings in the next few years. If it does, up to seven millions people could die from the disease.

     Diseases like bird flu are caused by viruses, that is, tiny things which change and become more dangerous

over time. When a new type of a common virus changes, it may be able to get past the body's immune (免疫

的) system. If that happens, humans are in great danger until a cure or treatment becomes available.

     There have always been viruses and people always get sick, of course, but as we saw with SARS, the

situation is more difficult today. People travel more than ever before, which means that disease can spread

quickly and across large areas-in fact the whole world.

     Scientists are already working on drugs that will prevent or limit the effect of a new virus, but the process

takes time. It is just as important to make sure that countries, especially poor countries, are prepared to deal

with the disease. New disease usually affect poor areas the most, so we must help develop health care in all

countries.

1. The situation is more serious today because _____. [ ]

A. people travel more

B. people don't eat healthy food

C. there aren't enough hospitals

D. scientists can't find a cure

2. From this passage we know _____. [ ]

A. bird flu will surely spread to human beings in the next few years

B. a virus changes and become less dangerous over time

C.SARS is 1ikely to come again in some years

D. poor areas usually suffers more from new diseases than rich areas

3. The possible title of this passage is _____. [ ]

A. The Work of WHO

B. Scientists Are Working Hard on Drugs for Diseases

C. What Is a Virus

D. Virus Changes and Causes New Diseases Over Time

干基型催化剂和湿基型催化剂的膨胀率是一样的。