题干

在一个不透明的不带中,红色、黑色、白色的乒乓球共有20个,除颜色外,形状、大小、质地等完全相同.小明通过多次摸球实验后发现其中投到红色、黑色球的频率稳定在5%和15%,则口袋中白色球的个数很可能是(  )

A:3个

B:4个

C:10个

D:16个

上一题 下一题 0.0难度 选择题 更新时间:2017-12-28 11:44:33

答案(点此获取答案解析)

D

同类题1

阅读下面四篇短文,从每题所给的A、B、C、D四个选项中选出最佳选项。

    The British government has started a£10- million Mandarin(普通话) Excellence Program. The program will see over 5,000 British students towards fluency(流利) in Mandarin Chinese by 2020.

    The program is led by local schools and supported by University College London. So far, 14 schools have taken part in the program.

    Hundreds of secondary school pupils in England have been taking lessons in Mandarin Chinese. Over the next three years, they will spend eight hours studying Mandarin Chinese every week.

    Nick Gibb is an officer of the British government. He said a high level of fluency in Mandarin Chinese would become more and more important. "Language skills are important for jobs and life in the global(* B)race. Mandarin Chinese is the most widely-spoken language in the world. It is one of the languages that matters the most to our country's future development. If the United Kingdom wants to remain competitive on the world stage, we do need far more of our young people leaving school with a good command of Mandarin Chinese, "Gibb added. "We hope that our young people could be given the chance to study the language. We want them to be fluent in both spoken and written Mandarin. The Mandarin Excellence Program will help us do this. It will not only broaden the students' minds, but give them a great advantage when they enter the world of work as well."

    British kids, in fact, are not alone. In America, about 200,000 students have been studying Mandarin Chinese. It is supposed that 800, 000 more will join them over the next couple of years.

同类题5

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    I have a friend named Monty Roberts who owns a horse ranch(牧马场). The last time I was there he told me his story. When he was young, his family was too poor to have a house to live in.As a result , when he was in high school, all the students were asked to write a paper about what they wanted to be and do when they grew up. That night he wrote a seven-page paper describing his goal of owning a horse ranch. He also drew a picture to show a 4,000-square-foot house that would sit on a beautiful farm. The next day he handed it in to his teacher. Two days later he received his paper back. On the front page was a large red F. Roberts asked, “Why did I receive an F?” He teacher said, “This is an unrealistic dream for a young boy like you. Owning a horse ranch requires a lot of money.” Then the teacher added, “If you will rewrite this paper with a more realistic goal, I will reconsider your grade.”

    The boy went home and thought about it for a long and hard time. He asked his father what he should do. His father said, “ Look, son, you have to make up your own mind on this. However, I think it is a very important decision for you.”Finally, after sitting with it for a week, the boy turned in the same paper, making no changes at all. He told his teacher “you could keep the F and I still keep my dream”.

    He tells me this story because I am sitting in his 4,000-square-foot house in the middle of the 200-acre horse ranch. “I still have that school paper now.” He added, “The best part of the story is that two years ago that  teacher brought 30 kids to camp out on my ranch for a week.” When the teacher was leaving, he said, Look, Monty, I can tell you this now. When I was your teacher, I was something of a dream stealer.During those years I stole a lot of kids' dreams. Luckily, you had enough gumption not to give up on yours. .”