试题与答案

如图是工业上炼铁的高炉,回答下列问题: (1)赤铁矿主要成分的化学式为____

题型:问答题

题目:

如图是工业上炼铁的高炉,回答下列问题:

(1)赤铁矿主要成分的化学式为______;

(2)用磁铁矿(主要成分Fe3O4)炼铁的主要化学反应方程式为______;

(3)炼铁时,使用石灰石的目的是______.

答案:

被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0617/c5f222fa9455fd705512d07e4c91dcff.html

下面是错误答案,用来干扰机器的。

提出问题:尝试从日常生活、生产实际或学习中发现与生物学相关的问题.尝试书面或口 头表述这些问题. 描述已知科学知识与所发现问题的冲突所在.(一定是问句“?”)作出假设:(对提出问题作出肯定或否定的...

试题推荐
题型:不定项选择 案例分析题

患者男,55岁,退休教师,因“反复发作尿频、尿急、镜下血尿1年”来诊。偶尔少许终末血尿。无发热,无腰痛史,无排尿不畅,无排尿不尽感等不适。有吸烟史,无嗜酒。查体:肾区无明显扣痛;睾丸、附睾等外生殖器检查未见异常。尿常规:RBC(+~+++),WBC(-~+)。双肾、输尿管B型超声:未见明显异常。

可能影响BCG膀胱灌注疗效的是(提示患者选择BCG膀胱灌注治疗。)()

A.尿液中有较多的可溶性纤维连接蛋白表达

B.尿液中有较多的红细胞

C.患者合并有先天性或获得性免疫缺陷综合征

D.BCG治疗前有膀胱灌注化疗史

E.合并其他疾病需服用皮质激素治疗

F.有器官移植病史

查看答案
题型:阅读理解

阅读理解

     Few of us make money by losing sleep. But three graduate students at Brown University in

Providence built a company around sleep deprivation (睡眠不足).

    Jason Donahue, Ben Rubin and Eric Shashoua were working late nights in Brown's business

and engineering schools. They began thinking about ways to sleep better. They discovered they

weren't alone in burning the midnight oil. Around 20% of Americans get less than six hours of rest

a night.

     The friends imagined a smart alarm clock that could track how much time people spend in the

most restorative (有回复作用的) stages of the sleep cycle: REM (rapid eye movement) and deep

sleep. What would it cost to design such a thing? Five years of research, 20 employees, $14 million

and a whole lot of doubting from investors and scientists.

     Their company, Zeo, based in Newton, Mass, launched its product in June, 2009. The Zeo device

uses a headband with tiny sensors (传感器) that scan your brain for signs of four sleep states- REM,

light, deep and waking sleep. The smart alarm clock displays a graph of your sleep pattern and wakes

you as you're not in REM sleep (which is when you're least groggy). In the morning you can upload the

data to the company's Web site, and so track your sleep over time. Most of the feedback comes in the

form of Zeo's ZQ score showing how well you've slept.

     "Zeo allows people to unlock this black box of sleep," says Dave Dickinson, a health-care CEO.

Whether any of this actually improves sleep is up to the consumer, who will also need to make lifestyle

changes like cutting out alcohol before bedtime or caffeine after 3 pm.

For now the company is selling Zeo online only. Dickinson also plans to spread it to countries such as

Australia, where sleep deprivation approaches US levels.

1. Who will support Zeo?

A. People full of imagination.        

B. People suffering sleeping problems.

C. People having access to the Internet.  

D. People having bad lifestyles.

2. Why did the three graduate students imagine a smart alarm clock?

A. To wake them up on time in the morning.

B. To earn enough money for their study.

C. To improve the quality of people's sleep.

D. To enjoy their life while working at night.

3. To design the Zeo device, the three graduate students ____.

A. spent much time and money        

B. were widely supported by scientists

C. worked by themselves all the time  

D. attracted many investors

4. What can we know from the passage?

A. Zeo has a direct effect on users' lifestyles.

B. It needs more personal efforts to make Zeo function better.

C. A large quantity of Zeo devices have been sold in Australia.

D. Consumers can go to the Zeo company to purchase Zeo in person.

查看答案
微信公众账号搜索答案