在关系DB中,任何二元关系模式的最高范式必定是A.1NF B.2NF C.3NF D

题型:单项选择题

问题:

在关系DB中,任何二元关系模式的最高范式必定是

A.1NF

B.2NF

C.3NF

D.BCNF

考点:计算机等级考试数据库技术三级数据库技术笔试309
题型:单项选择题

“头上两根感觉触,两对翅,三对足,身体分为头胸腹,里头是肉外是骨”描写的是哪类生物的主要特点:[ ]

A.节肢动物

B.昆虫

C.鱼类

D.鸟类

题型:单项选择题

男,58岁,进食梗阻感,结合图像,最可能的诊断为()

A.正常食管

B.食管静脉曲张

C.食管平滑肌瘤

D.食管上段癌

E.食管下段癌

题型:单项选择题

明洞衬砌施工的方法有()。

A、先墙后拱法;

B、先拱后墙法;

C、墙拱交替法;

D、跳槽挖井法;

E、拱墙整体灌筑;

F、台阶法。

题型:单项选择题

     A few years I was on a bicycle trip when I got off my bike for a rest. I sat down on the grass. A few

seconds later, I was covered in ants. They were swarming all over me so I got up and brushed them off.

It was a strange experience but I soon forgot about it.

     A couple of years later, I was living in Jordan. I had just moved into a modern flat and was unpacking

plates when I saw something move out of the corner of my eye. I looked over at the kitchen drawer and

there was a cockroach(蟑螂) crawling out of it. I screamed. Then I grabbed a can of insecticide and

sprayed it on the cockroach. He ran under the nearby bathroom door. It took me three days before I

found the courage to open the bathroom door to see if he was still alive. He wasn't.

     Why did I react so violently to one lone insect when a closer encounter with hundreds of ants hardly

affected me? The answer is easy: because cockroaches are creepy crawlies(令人害怕的爬虫) and ants

aren't. Creepy crawlies are those little bugs which provoke feelings such as apprehension(忧虑), anxiety

or aversion(讨厌) - they make your skin crawl.

     Did you know that some people feel such a fear of bugs that it becomes a phobia(恐惧)?

Psychologists have offered many explanations. Some say we associate them with dirt and disease. Or

that these are life forms that are so alien to us, that we find them repulsive(排斥的) for their dissimilarity.

     Insects, however, don't follow our rules - they just do what they want and invade our space.

Unfortunately, although insects and bugs have been a successful animal species up to now, many of them,

like many other species nowadays, are under threat of extinction. Entomologists(昆虫学家) warn that

this could upset entire ecosystems and lead to all kinds of disastrous consequences. So my plea to you is:

the next time you feel the urge to stamp on, splatter or spray a creepy crawly, give a thought to the planet

and stop.

1. Why did the author mention the ants in the beginning?

A. Because the experience with the ants presents a sharp contrast to that with the cockroach later.

B. Because the author wants to show her preference to the ants and her dislike for the cockroach.

C. Because both ants and cockroaches are creepy crawlies that the author dislikes.

D. Because meeting the ants is an unusual experience that the author can hardly forget.                              

2. What does "insecticide" in the second paragraph probably mean?                            

A. A kind of fruit juice.

B. A kitchen knife.

C. Liquid for killing insects.

D. Cleanser for the bathroom.                                                                                                               

3. How does the author feel about the bugs like cockroaches?

A. The author doesn't mind the contact with those harmless small creatures.

B. They make the author feel so awful that they should be killed.

C. They invade our space and become a threat to humans.

D. They still deserve a place for keeping the balance of the nature.hundreds of ants.

4. Which of the following is NOT the reason why the cockroach makes the author's skin crawl?

A. It looks so strange and different that the author can't accept its appearance.

B. It can make the author feel sick and cause a strong dislike.

C. The author may relate it to something dirty or disease at the sight of it.

D. It reminds the author of the experience of meeting

5. Which of the following statements about bugs is NOT true according to the passage?

A. Some people may be frightened so much by bugs that it leads to a psychological barrier in some

degree.

B. People can enjoy a cleaner living environment if more bugs like cockroaches are killed.

C. Many bugs are in danger of extinction so they should be placed under human's protection.

D. Some bugs are extremely unpleasant that people have a strong wish to destroy them.

题型:单项选择题

城院的“红卡”是我们参加活动()?

A.直接性动机

B.替代性动机

C.预期性动机

D.内在动机

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