题干

若集合A=x|x-23,xR,B=y|y=1-x2,yR,则A∩B =(  )

A:0,1

B:0,+∞)

C:-1,1

D:

上一题 下一题 0.0难度 选择题 更新时间:2018-06-06 05:15:42

答案(点此获取答案解析)

C

同类题1

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.

    What's your opinion on spicy food? Some people cannot handle even the smallest amount of chili(辣椒) in their dinner while others can't get enough of it.       

Scientists have long been puzzled by why some people love chili and others loathe it. Plenty of research has been done on the subject, dating back to as far as the 1970s. Previous results showed that a love of chili is related to childhood experiences, and cultural influences affect our taste buds, too. But the latest study has found that a person's love of spicy food may be linked to his or her personality more than anything else, CBC News reported.

     “We have always assumed that liking drives intake---we eat what we like and we like what we eat. But no one has actually directly bothered to connect these personality traits with intake of chili peppers,” said Professor John Hayes from Pennsylvania State University, who led the study.       

But before you look at the study, you should first know that “spicy” is not a taste, unlike sour, sweet, bitter and salty. It is, in fact, a burning sensation that you feel on the surface of your tongue. This got scientists thinking that maybe a love of spicy food is brought about by people's longing for thrill, something they usually get from watching action movies or riding a roller coaster.

In the study, 97 participants, both male and female, were asked to fill out questionnaires about certain traits of their personality, for example. Whether they like new experiences or tend to avoid risks. They were then given cups of water with capsaicin(辣椒素), the plant chemical that makes chili burn, mixed into them.

By comparing the answers to questionnaires and what participants said they felt about the spicy water. Researchers found that those who most tended to enjoy action movies or take risks were about six times more likely to enjoy the spicy water.

    Interestingly, we used to believe that the reason some people can withstand spicy food is that their tongue have become less sensitive to it. However, this latest study has found otherwise. It's not that it doesn't burn as badly, it's that you actually learn to like the burn,” Hayes explained.  

同类题2

阅读下文,回答问题

    中国传统的文学以诗文为正宗,大多数出于士大夫之手。士大夫配合君主掌握着政权。做了官是大夫,没有做官是士;士是候补的大夫。君主士大夫合为一个封建集团,他们的利害是共同的。这个集团的传统的文学标准,大概可用“儒雅风流”一语来代表。载道或言志的文学以“儒雅”为标准,缘情与隐逸的文学以“风流”为标准。

    “诗言志”这一个语在开始出现的时候,原也是一种尺度;后来得到公认而流传,就成为一种标准。说陆机用了新的尺度,是对“诗言志”那个旧尺度而言。这个新尺度后来也得到公认而流传,成为又一种标准。又如南朝文学的求新,后来文学的复古,其实都是在变化;在变化的时候也都是用着新的尺度。固然这种新尺度大致只伸缩于“儒雅”和“风流”两种标准之间,但是每回伸缩的长短不同,疏密不同,各有各的特色。

    这种尺度表现在文论和选集里,也就是表现在文学批评里。中国的文学批评以各种形式出现。魏文帝的“论文”是在一般学术的批评的《典论》里,陆机《文赋》也许可以说是独立的文学批评的创始,他将文作为一个独立的课题来讨论。此后有了选集,这里面分别体类,叙述源流,指点得失,都是批评的工作。又有了《文心雕龙》和《诗品》两部批评专著。还有史书的文学传论,别集的序跋和别集中的书信。这些都是比较有系统的文学批评,各有各的尺度。这些尺度有的依据着“儒雅”那个标准,结果就是复古的文学,有的依据着“风流”那个标准,结果就是标新的文学。但是所谓复古,其实也还是求变化求新异;韩愈提倡古文,却主张务去陈言,戛戛独造,是最显著的例子。古文运动从独造新语上最见出成绩来。胡适之先生说文学革命都从文字或文体的解放开始,是有道理的,因为这里最容易见出改变了的尺度。现代语体文学是标新的,不是复古的,却也可以说是从文字或文体的解放开始;就从这语体上,分明的看出我们的新尺度。

(选自朱自清《文学的标准与尺度》,有删改)