问题 选择题

关节炎病因是在关节滑液中形成尿酸钠晶体,尤其在寒冷季节能诱发关节疼痛,其化学机理为:①HUr(尿酸)+H2O⇌Ur-(尿酸根离子)+H3O+;②Ur-(aq)+Na+ (aq)⇌NaUr(s).下列对反应②的叙述中正确的是(  )

A.反应的△H<0

B.降低温度,平衡向逆反应方向移动

C.反应的△H>0

D.升高温度,平衡向正反应方向移动

答案

由题目信息可知,关节炎病因是在关节滑液中形成尿酸钠晶体,尤其在寒冷季节能诱发关节疼痛,说明温度越低,越有利于尿酸钠的形成,温度降低平衡向正反应进行,降低温度平衡向放热方向移动,故反应②是放热反应,即△H<0,升高温度平衡向逆反应方向移动,故BCD错误、A正确,故选A.

单项选择题
阅读理解

阅读理解。

     On a hill 600 feet above the surrounding land, we watch the lines of rain move across the scene, the

moon rise over the hills, and the stars appear in the sky. The views invite a long look from a comfortable

chair in front of the wooden house.

    Every window in our wooden house has a view, and the forest and lakes seldom look the same as the

hour before. Each look reminds us where we are.

    There is space for our three boys to play outside, to shoot arrows, collect tree seeds, build earth

houses and climb trees.

    Our kids have learned the names of the trees, and with the names have come familiarity and

appreciation. As they tell all who show even a passing interest, maple(枫树)makes the best fighting sticks

and white pines are the best climbing trees.

    The air is clean and fresh. The water from the well has a pleasant taste, and it is perhaps the healthiest

water our kids will ever drink. Though they have one glass a day of juice and the rest is water, they never

say anything against that.

    The seasons change just outside the door. We watch the maples turn every shade of yellow and red in

the fall and note the poplars'(杨树)putting out the first green leaves of spring. The rainbow smelt fills the

local steam as the ice gradually disappears, and the wood frogs start to sing in pools after being frozen for

the winter. A family of birds rules our skies and flies over the lake.

1. What can be learned from Paragraph 2?

A. The scenes are colorful and changeable.

B. There are many windows in the wooden house.

C. The views remind us that we are in a wooden house.

D. The lakes outside the windows are quite different in color.

2. By mentioning the names of the trees, the author aims to show that ______ .

A. the kids like playing in trees

B. the kids are very familiar with trees

C. the kids have learned much knowledge

D. the kids find trees useful learning tools

3. What does the underlined sentence in the last paragraph mean?

A. The change of seasons is easily felt.

B. The seasons make the scenes change.

C. The weather often changes in the forest.

D. The door is a good position to enjoy changing seasons.

4. What is the main purpose of the author writing the text?

A. To describe the beauty of the scene around the house.

B. To introduce her children's happy life in the forest.

C. To show that living in the forest is healthful.

D. To share the joy of living in the nature.