题干

1986年中国人民银行发行了“中国杰出历史人物纪念币”第三组,共五枚金银币。其中一枚为图3所示的祖冲之,在银币正面头像右上方有一圆形,其内部有“祖率”二字(国际上曾经有人提议将圆周率定名为“祖率”)。根据图示并结合所学知识,今天我们纪念祖冲之的主要原因是(    )

A:编撰了数学名著《缀术》

B:将圆周率精确到小数点后第七位

C:创制了最先进的历法《大明历》

D:他擅长机械制造

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答案(点此获取答案解析)

B

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    Often people receive a guitar, mandolin, or some other musical instrument as a birthday or Christmas gift. There's joy everywhere. The giver of the gift knows how much the receiver wants to learn this instrument and the receiver is actually holding it in his hands instead of longing for it through the shop window.

    Finding an instructor that fits into a busy work schedule is hard enough, but once you decide on a lesson plan, then you must consider the practice time, how to practice, what to practice—and let's face it...not all people learn something the same way. So in order to learn a musical instrument, how much practice time is enough and what kind of practice is right for you?

    There is no set amount of time that anyone should practice a musical instrument. When I was in programming classes, I could have studied nightly for 5 hours each night. It would have taken me years to learn the art of computer programming. Though I'm attracted by the systematic logic of it, my talent is towards another thing. However, on the other hand, if I spent an hour every couple days with a passionate hobby like playing the violin, not only would the time fly quickly...I'd also be learning at a much greater speed since the built-in passion is the motivation for advancement.

    So as much as it's important to practice, a step back is to first find the harmonious instrument that fits you as a person; as development of your personality. If you're learning the guitar because it's cool....obviously that's the modern-day mindset, however, you might not be actually linking your talent for musical satisfaction with your most creative advantages you have to offer.

    It's been my experience that every person has a certain level of musical talent. My pleasant challenge has been to assist them in this adventure and actually locate their best abilities as quickly as possible. Then and only then can we match learners with instruments and truly begin a fun and exciting walk down the road of happiness and contentment, where music, ability, personality and soul all meet. Once this piece of the mystery puzzle is in place, I've never had to work at motivating a learner to practice...