长途运输鱼苗的容器内必须满足下列条件才能保持鱼苗的存活:充足的氧气、鱼苗呼出的二

题型:选择题

问题:

长途运输鱼苗的容器内必须满足下列条件才能保持鱼苗的存活:充足的氧气、鱼苗呼出的二氧化碳要及时除去、防止细菌繁殖、水的pH在8左右。现有以下3种具有杀菌能力的物质供选择使用:双氧水、过氧化钙(CaO2)、过氧化钠(Na2O2),它们在容器内可发生如下反应:

(1)2H2O2=2H2O+O2↑       

(2)2Na2O2+2H2O=4NaOH+O2↑    (3)2Na2O2+2CO2=2Na2CO3+O2   

(4)2CaO2+2H2O=2Ca(OH)2+O2↑   (5)2CaO2+2CO2=2CaCO3+O2

你认为最合适的物质是

A.双氧水

B.过氧化钙

C.过氧化钠

D.双氧水与过氧化钠组合

考点:酸的性质浓硫酸的稀释生石灰的性质和用途碱的用途
题型:选择题

败酱科的特征是:

A.全株具有强烈的臭气和香气

B.叶互生

C.雄蕊3枚

D.雄蕊5枚

E.子房上位 子房下位

题型:选择题

第三部分 阅读理解(共20小题;每小题2分,满分40分)

第一节 阅读下列短文,从每题所给的四个选项(A、B、C和D)中,选出最佳选项,并在答题卡上将该项涂黑。

A

When I was a kid, I always used to wonder how in the world my father work outside in the winter without a coat. It could be minus 20 degrees centigrade and there’d be Dad, removing snow, or perhaps chopping some wood --- his coat thrown aside--- wearing a shirt , a cap, and a pair of gloves.

“Aren’t you cold, Dad?” I’d ask. “No,” Dad would reply. “I’m not cold--- working too hard to be cold.”

Many times I wondered whether my father was an extremely tough man, or whether he was foolish.

One time when I was quite young, perhaps five or so, I went ice fishing with Dad. It was a bright, clear day—and bitterly cold.

After we’d been out on the ice for a little while, my feet started getting cold.

“ Daddy, my feet are cold.” I said.

“Yeah, it’s cold out here today,” he replied.

“Tell you what,” he said. “Walk around. Make some circles in the snow. See how many different patterns you can make. That will get your feet warm.”

Now, I was just a little girl at the time but I remember thinking, “How in the world will walking around in the snow make my feet warm? Dad must be out of mind.

But he was my father, after all. I made circles in the snow. I made squares. Pretty soon I was having so much fun making patterns in the snow. I forgot about my feet being cold.

Now, all these years later, I know, too, from personal experience how my father was able to take his coat off and work outside in the winter wearing just a shirt, a cap and gloves. Because I do it, too. “Aren’t you cold?” my husband asked one winter day. “No,” I replied. “I’m not cold—working too hard to be cold.”

I hope my husband has decided I’m both tough and smart. But I guess quite a bit of the time he thinks I’m foolish.

Wherever Dad is in that great big farm in the sky—I’m sure he can’t help but smile whenever I take my coat off while I’m working outside in the winter.

51. When the author’s feet felt cold, her father advised her to____.

A. go home alone first        B. keep walking in the snow

C. draw pictures in the snow    D. light a fire on the ice

52. Hearing her father’s advice, the author thought her father____.

A. forgettable      B. warm-hearted         C. crazy              D. cruel

53. What might the author’s husband think of her?

A. Tough            B. Smart                    C. Brave             D. Foolish

54. The author’s purpose of writing this passage is to ______.

A. remember her tough and smart father

B. show how her father cared about her

C. describe memories of her childhood

D. explain why her father loved her so much

题型:选择题
利用实验器材(规格和数量不限),能完成相应实验的一项是(  )

实验器材(省略夹持装置)相应实验
A烧杯、玻璃棒、蒸发皿硫酸铜溶液的浓缩结晶
B烧杯、玻璃棒、胶头滴管、滤纸用盐酸除去硫酸钡中的少量碳酸钡
C烧杯、玻璃棒、胶头滴管、容量瓶用固体氯化钠配制0.5mol/L的溶液
D烧杯、玻璃棒、胶头滴管、分液漏斗用溴水和CCl4除去NaBr溶液中的少量NaI

A.A

B.B

C.C

D.D

题型:选择题

注水系统会记录最后()内接收的所有模拟参数

A、5分钟

B、30分钟

C、10分钟

D、45分钟

题型:选择题

船舶在旋回运动中,漂角何处最大()?

A.转心处

B.重心处

C.船尾端

D.船首端

更多题库