问题 选择题

下列有关原电池和电解池的叙述中正确的是(  )

A.钢管大部分浸在淡水中,主要发生析氢腐蚀

B.钢管若采用外加电流的阴极保护措施,应当与电源的正极相连

C.钢管若需保护,可采用牺牲阳极的阴极保护法

D.电解氯化钠溶液时电子从负极经过溶液流向正极

答案

A、中性溶液中金属的腐蚀以吸氧腐蚀为主,强酸性环境中,金属主要发生析氢腐蚀,故A错误;

B、活泼金属作阳极,则在阳极上放电的是金属,会加快金属的腐蚀,故B错误;

C、金属做原电池的正极(即发生还原反应的阴极)可以被保护,故C正确;

D、电解池中,阳极为失去电子的极,电子从阳极经外电路流向阴极,故D错误.

故选C.

填空题
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 \

As a young man Glenn Kurtz wanted to ______.

A.surpass Andres Segovia’s achievement

B.Transform classical guitar

C.become a TV music star

D.live on arts