题干

下列有关盐酸和酒精的叙述,正确的是(  )

A:酒精是酵母菌无氧呼吸的产物,可使溴麝香草酚蓝水溶液由蓝变绿

B:酒精是良好的有机溶剂,“绿叶中色素的提取和分离”可用无水乙醇作为提取液

C:“观察根尖有丝分裂”实验中使用盐酸是为了促进染色质中DNA与蛋白质分离

D:利用盐酸改变膜的通透性,然后使用健那绿染色,观察口腔上皮细胞中的线粒体

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B

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    Street art is a very popular form of art that is spreading quickly all over the world. You can find it on building, sidewalks, street sings and trash cans from Tokyo to Paris, and from Moscow to Cape Town. Street art has become a global culture and even art museums and galleries are collecting the works of street artists. Even advertising companies also use street art in their ads due to its popularity.

    Street art started out very secretly because it's illegal to paint on public and private property without permission. People often have different opinions about street art. Some people think it is a crime with others think it's a new form of culture.

    Art experts claim that the movement began in New York in the 1960s. Young adults sprayed words and images on walls and trains. This colorful and energetic style of writing became known as graffiti(涂鸦). Graffiti art showed that young people wanted to rebel against society. They didn't want to accept rules, and they travelled around cities to create paintings that everyone could see. In many cases, they had trouble with the police and the local government.

    Many street corners in Paris show the works of Space Invader. A French artist uses small pieces of glass to make images of space creatures. He has been doing this for some years and the police have arrested him a few times. On his website, you can see many other places where he has created this form of art.

    Street artists do their work for some reasons. Some of them do not like the artists who make so much money in galleries and museums. They choose street art because it is closer to common people. Some artists try to express their political opinion in their works. They often want to protest against big firms and corporations. Others like to do things that are forbidden and hope they don't get caught.

    In today's world, the Internet has a big influence on street art. Artists can show their pictures to people all over the world. Many city residents, however, say that seeing a picture on the Internet is never as good as seeing it alive. The street art movement lives with the energy and life of a big city. There it will continue to change and grow.