题干

如图是同一显微镜观察同一植物组织标本4次得到的图象,下列推测正确的是(    )

A:④所用的目镜的放大倍数一定大于③

B:③视野一定比④视野亮

C:图象③中能非常清楚的看到细胞膜

D:若目镜没有变,则观察视野②时用的物镜比观察③时用的物镜短

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D

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    In today's Internet age, the demand for online games continues to grow. Online computer game centers exist in many cities and towns throughout Asia. Facing the pressures of school and life, people turn to the virtual world, expecting a diversion from these problems. Too often, however, they can lead to problems and unhealthy addictions.

    This is most clearly seen in the example of South Korea. The country has the world's highest percentage of high-speed Internet services. It also has a high number of online game players and related problems. In 2013, a young man collapsed and died while playing online games. He had been playing almost nonstop for 86 hours at an Internet cafe. Another young man killed his sister after becoming confused between the online world and real life. A 12-year-old boy stole US $ 16,000 from his father and ran away from home. He did this to continue his obsession with an online game. Such problems, however, don't just happen in South Korea. They are spreading to other parts of Asia, as well.

    What kinds of people develop online game addiction? What does the problem look like? Dr. SueHuei Chen, a clinical psychologist, researches Internet addiction. She discovered some signs of at-risk individuals such as lack friendships and good social skills. Those problem individuals feel it so compulsive to play online games that they could sacrifice things such as school or family. They feel the need to spend more and more time online. And they become upset if anyone tries to limit their online game playing.

    How many problem game players are there? In mainland China, the potential number of problem online gamers is alarming. In 2014, the China Daily reported that China had 13.8 million online game players. Furthermore, it stated that 80 percent of these were under 25 and had signs of addiction. Such numbers point toward a growing problem among Chinese youth.

Make sure to keep control over your online game playing. If you don't control it, it can get control of you.