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关于x的不等式acos2x+cosx≥﹣1恒成立,则实数a的取值范围是____.
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    French writer Frantz Fanon once said: "To speak a language is to take on a world, a culture." Since the world changes every day, so does our language.

    More than 300 new words and phrases have recently made it into the Oxford Dictionary Online, and in one way or another they are all reflections of today's changing world.

    After a year that was politically unstable, it's not hard to understand the fact that people's political views are one of the main drives of our expanding vocabulary. One example is "clicktivism", a compound of "click" and "activism". It refers to "armchair activists" -- people who support a political or social cause, but only show their support from behind a computer or smart phone.

    "We had all the words around Brexit (脱欧) in the last update and we are now starting to see all the words around Trump coming into the dictionary," Angus Stevenson, Oxford Dictionaries' head of content development, told The Guardian.

    Lifestyle is also changing our language. For example, "fitspiration -- a compound of fit and inspiration -- refers to a person or thing that encourages one to exercise and stay fit and healthy. The phrase "climate refugee" -- someone who is forced to leave their home due to climate change -- reflects people's concern for the environment.

    According to Stevenson, social media was the main source for the new expressions "People feel much freer to coin their own words these days." he said.

    But still, not all newly- invented words get the chance to make their way into a mainstream dictionary. If you want to create your own hit words, Angus Stevenson suggests that you should not only make sure that they are expressive and meaningful, but also have an attractive sound so that people will enjoy saying them out loud.

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    Hilversum is a medium-sized city between the major cities of Amsterdam and Utrecht in the Gooi area of North Holland, the Netherlands. Unlike most of the Netherlands, Hilversum is actually in a hilly area with the soil mostly consisting of sand. Once called the Garden of Amsterdam, it still attracts travelers to come over to cycle and walk through the surrounding forests. They visit it for a relaxing day off from the urban madness. For Dutch people, Hilversum is all about textile (纺织) and media industries, and modern architecture.

    In history, Hilversum was largely an agricultural area. Daily life was marked by farming, sheep raising and wool production. A railway link to Amsterdam in 1874 attracted rich traders from Amsterdam to Hilversum. They build themselves large villas (别墅) in the wooded surroundings of the town. One of the families moving in was the Brenninkmeijers, currently the wealthiest family of the Netherlands. They moved in after big success in the textile industry and aided a substantial textile industry in Hilversum. But the textile boom lasted only several decades. The last factory closed in the 1960s.

    The change to a media economy started in 1920, when the Nederlandse Seintoestedllen Fabriek (NSF) established a radio factory in Hiversum. Most radio stations called in the large villas in the leafy areas of the town. Television gave another push to the local economy. Hilversum became the media capital of the Netherlands, and Dutch televison stars moved into the leafy neighborhoods surrounding the town.

    In the early 1900s, modern architcts W.M. Dudok and J. Duiker placed hundreds of remarkable buildings in Hilversum. These modern architectural masterpieces (杰作) are so many that Hilversum almost feels like an open air museum. Dudok alone shaped most 20th century Hilversum and approximately 75 buildings in 1928-1931. It has wide international fame and is included in many architecture textbooks. The building has a remarkable shape and looks like a combination of “blocks”. Actually, one may start his journey of modern architecture by walking or biking the W.M. Dudok Architectural Route in Hilversum.