问题 单项选择题

设每发生某种事件的概率P很小,如不改变这种情况,长此下去,这种事件几乎可以肯定是会发生的。对上述说法,适当的数字描述是:设0<p<1,则()

A.

B.

C.

D.

答案

参考答案:C

解析:

依题意可得到以下两个条件:当n=1,p→0;当n→∞,p=1。将这两个条件分别代入本试题的4个选项,只有选项C满足条件。具体解答情况如下。

对于选项A,当n=1,p→0时,;当n→∞,p=1时,

对于选项B,当n=1,p→0时,;当n→∞,p=1时,

对于选项C,当n=1,p→0时,;当n→∞,p=1时,

对于选项D,当n=1,P→0时,;当n→∞,p=1时,

判断题
单项选择题

Writing about music is like dancing about architecture, or so the saying goes. Sometimes attributed to Frank Zappa, other times to Elvis Costello, this quote is usually intended to convey the futility of such an endeavor, if not the complete silliness of even attempting it. But Glenn Kurtz’s graceful memoir, Practicing: A Musician’s Return to Music, turns the expression on its head, giving it a different meaning by creating a lovely, unique book.
Kurtz picked up the guitar as a kid in a music-loving family, attended the Long Island music school, and went on to play on Merv Griffin’s TV show before graduating from Tufts University. Motivating the young Kurtz was the dream of reinventing classical guitar, as if by his great ambition alone he could push it from the margins of popular interest to center stage-something not even accomplished by the late Spanish guitarist Andres Segovia, perhaps the only artist of the form ever to reach anything resembling widespread celebrity.
This book reads like a love story of sorts: Boy meets guitar. Boy loves guitar. Guitar breaks boy’s heart or, more precisely, the ordinariness of a working musician’s life does so. "I’d just imagined the artist’s life naively, childishly, with too much longing, too much poetry and innocence and purity," Kurtz writes. "The guitar had been the instrument of my dreams. Now the dream was over. "
Boy leaves guitar. Were the story to end here, this book would be a tragedy, but after nearly a decade the boy returns to guitar, and although he has lost the enthusiasm he had in his youth, he finds his love of the guitar again in a way he never could have appreciated before.
Although Kurtz is writing about a unique musical path, his journey speaks eloquently to the heart of anyone who has ever desperately yearned to achieve something and felt the sting of disappointment. "Everyone who gives up a serious childhood dream—of becoming an artist, a doctor, an engineer, an athlete—lives the rest of their life with a sense of loss, with nagging what it is," he writes. "Is that time and effort, that talent and ambition, truly wasted \

Paragraph 3 suggests that what "the ordinariness of a working musician’s life" does to the boy is ______.

A.keep him in great excitement

B.bring him great disappointment

C.help him create great music

D.tell him a great musician’s duty