下列命题正确的是()。 A.分段函数必存在间断点 B.单调有界函数无第二类间断点 C

题型:单项选择题

问题:

下列命题正确的是()。

A.分段函数必存在间断点

B.单调有界函数无第二类间断点

C.在开区间连续,则在该区间必取得最大值和最小值

D.在闭区间上有间断点的函数一定有界

考点:电气工程公共基础第一章数学第一章数学题库
题型:单项选择题

根据短文内容,判断正(T)误(F)。

    Many young people can use a computer, but few of them know how to look after it. Remember the

following tips when you use a computer.

    Keep your computer in a cool, dry room. Too much or too little heat is bad for computers. Damp

(潮湿) is also bad for them. Most computers work best at a temperature of 5-10 degrees centigrade

(摄氏度).

    Do not let people smoke cigarettes near your computer. Smoke of all kinds is very bad for many parts

of the computer and can cause many problems.

    Do not eat or drink when you are near your computer. Pieces of food or drops of water on the keyboard

can also cause many problems.

    Make sure that the keyboard and the screen are the correct height for you. If they are not correct, you

will get backache.

    Make sure the screen is the correct distance from your eyes. If you wear glasses, make sure these

glasses are correct for using with the computer. Some people use a different pair of glasses when they

use a computer.

    Keep your screen clean and do not have it too bright. A dirty screen can hurt your eyes. A very bright

screen can also be bad for your eyes. If you can afford one, buy a computer screen. It will be better for

you than using the screen of a TV set.

    Never use any software (软件) that you don't know whether they are clean or not. You must be careful

because some software can bring viruses (病毒) into the computer. If your computer has viruses, it can't

work or even breaks down.

( )1. According to this passage, most young people can control computers well while paying little

           attention to the keeping of them.

( )2. Putting the keyboard and the screen too high means you don't have to look at your manuscript

            (手稿) while typing.

( )3. Some people use a different pair of glasses when they use a computer because they want to

            protect their eyes.

( )4. It's better to use a TV set screen instead of a computer one because a TV set is usually larger

            than a computer one.

( )5. "Clean software" means the software without any viruses.

题型:单项选择题

()常作为代乳糖的混合物。

A.淀粉、糊精、蔗糖

B.淀粉、糊精、果糖

C.淀粉、糊精、葡萄糖

D.蔗糖、果糖、葡萄糖

题型:单项选择题

四逆汤的组成是()

A.金礞石(煅)、黄芩、熟大黄、沉香

B.胆南星、酒黄芩、瓜蒌仁霜、苦杏仁、陈皮、枳实、茯苓、半夏(制)

C.半夏(制)、陈皮、茯苓、甘草

D.地黄、玄参、麦冬、白芍、牡丹皮、川贝母、薄荷、甘草

E.淡附片、干姜、炙甘草

题型:单项选择题

项目建议书和可行性研究的区别,说法不正确的是( )。

A.从研究的范围和内容上看有很大区别
B.项目建议书阶段所做的只是对建设项目的一个总体设想,主要是从宏观上考察项目的必要性和主要建设条件是否具备,确定是否要推荐此项目,有没有价值投入更多的资金和人力进行深入的可行性研究工作,以防盲目建设
C.项目建议书是建设程序的最初阶段,主要是依据国民经济和社会发展长远规划,以及行业、地区规定、国家产业政策、技术政策、生产力布局状况,自然资源状况等宏观的信息
D.项目建议书阶段的研究目的是推荐项目,建议是否进一步做可行性研究;而可行性研究阶段,则是要通过分析比较,择优提出详细工程方案,详细计算项目投入的资金和产出的效益等,它是项目立项的决策文件

题型:单项选择题

20世纪初,Forssman用豚鼠肝、脾、肾上腺等脏器制备的生理盐水悬液免疫家兔获得的抗体,除能与原来的相应的脏器抗原反应外,还可使绵羊红细胞发生凝集,出现这一现象是因为()。

A.绵羊红细胞发生了自身凝集

B.豚鼠某些组织与绵羊红细胞之间存在共同抗原决定簇

C.豚鼠与绵羊之问有完全相同的血型抗原

D.豚鼠脏器在制备悬液过程中其抗原结构发生了改变

E.体外实验中,绵羊红细胞的抗原发生了改变

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