试写出图象位于第二、四象限的一个反比例函数的解析式______．

阅读理解。

     Cold air. Snow. Shorter days. We are in winter now.

     Winter is the coldest season of the year. It comes between autumn and spring. For us, the winter

months are usually November, December and January. But that is only because we live in the northern

part of the Earth.

     In China, winter is the time between the beginning of winter, and the beginning of spring. But, this

is the time that the southern part of the Earth, has its summer. Imagine when we are playing with snow,

Australian kids are enjoying ice cream!

     Winter isn't always gray. It can also be bright. Here's how.

     Put on a holiday play and try acting. Ask your cousins or classmates to come to your house and make

beautiful clothes and write a play. Act it out for your family.

     Play around. Go outside and enjoy yourself. Make a snowman with your friends.

     If you really have to stay indoors, give your room a clean and decorate (装饰) it. You'll find it a lot

of fun.

1. What does this passage mainly talk bout? [ ]

A. The winter season and fun winter activities.

B. Ways to decorate houses.

C. The difference between China and Australia.

D. The colours linked to winter.

2. Why are Australian kids eating ice cream when it's winter in China? [ ]

A. Because they are crazy about ice cream.

B. Because winter in Australia is not as cold as that in China.

C. Because it's summer in Australia when it's winter in China.

D. Because they don't have much to do in winter.

3. Which of the following statements is NOT true according to the passage? [ ]

A. The northern and southern parts of the Earth have different winter months.

B. Winter can be fun if you find interesting things to do.

C. The writer thinks it's great fun to clean your house and decorate it.

D. Australian kids enjoy having ice cream on winter days.

从短文中选出一种你喜欢的活动，并说明原因。 

     I think it will be great fun to 4. ____ this winter because I like to 5. ____. Also, it is 6.____ and it can

7.____. I'll try it out soon. 

Find words from the passage to fill in the blanks:

     In China, the winter months are usually November, December and 8.____. But it's different in Australia.

The winter in China is 9.____ in Australia because it is in the 10.____ part of the Earth.

     Winter is not always 11.___. You can have lots of fun. Try 12.____ a play and acting it out with your

cousins or friends. Or you can play 13.____ outside and make a 14.____. If you have to stay 15.____, clean

up your house and 16.____ it with fun pieces.

     Just enjoy winter!

特发性血小板减少性紫癜病人的主要发病机制是()。

A．机体产生抗血小板抗体

B．骨髓造血功能衰竭

C．凝血因子缺乏

D．小血管的变态反应性炎症

E．凝血和纤溶失衡

阐述超文本式浏览器工具WWW的工作原理。

水稻白叶枯病的初侵染源是病稻草和种子。

安健环体系与三标等体系最大的区别是（）

A.三标体系建设是企业行为

B.安健环体系建设是企业行为

C.安健环体系建设是政府行为

D.安健环与三标等体系无本质区别