元子^①家有乳母为圆转之器，以悦婴儿，婴儿喜之，母聚孩孺助婴儿之乐。友人公植者，闻有戏儿之器，请见之。及见之，趋焚之。责元子曰：“吾闻古之恶圆之士歌曰：宁方为皂^②，不圆^③为卿^④，宁方为污辱，不圆为显荣。次山奈何任造圆转之器，恣令悦媚婴儿？少喜之，长必好之。教儿学图且陷不义，躬自戏圆又失方正。嗟！嗟！次山入门爱婴儿之乐圆，出门当爱小人之趋圆，吾安知次山异日不言圆，行圆，以终身乎？吾岂次山之友也！”

       元子召季川^⑤谓曰：“吾自婴儿戏圆，公植尚辱我，言绝忽乎。吾与汝圆以应物，圆以趋时，非圆不预^⑥，非圆不为，公植其操矛戟刑我乎！”

（作者：元结选自《唐文粹》，有删改）

     【注释】①元子：元结，字次山，唐代古文运动的先驱之一。②皂：皂隶，泛指从事低贱行业的人。③圆：圆滑。④卿：公卿，泛指高官。⑤季川：元结的堂弟。⑥预：参与。

阅读下文，回答相关问题。

                                                                                                      情抱
       唐相国孙公宽裕通简，不事矫异，常语于亲友曰：“凡人许己，务在得中。但士行无亏，不必太苦。以我之长彰彼之短以我之清彰彼之浊幸勿为之。”后谪居衡山，情抱坦然，不以放逐而怀戚戚。每对客座，而厮仆辈纷诟殴曳，仆于面前。相国凝然似无所睹，谓客曰：“若以怒心逢彼，即方寸自挠矣。”其性度皆此类也。相国曾乘轺至蜀，诣杜光庭先生受，乃曰：“尝遇至人，话及时事，每有高栖之约。”尔后虽登台辅，竟出官于南岳，有诗《寄杜先生》，其要句云：“蜀国信难遇，楚乡心更愁。我行同范蠡，师举效浮丘。他日相逢处，多应在十洲”。唐末朝达罹谷水白马驿之祸，唯相国获免焉。

已知圆C与直线x－y="0" 及x－y－4=0都相切，圆心在直线x+y=0上，则圆C的方程为（    ）

    Once there was a piano player in a bar. People came just to hear him play. But one night, a girl asked him to sing a song.

    “I don't sing,” said the man.

    But the girl told the waiter, “I'm tired of listening to the piano. I want the player to sing! ”

    The waiter shouted across the room, “Hey, friend! If you want to get money, sing a song!”

    So he did. He had never sung in public before. Now he was singing for the very first time! Nobody had ever heard the song!

    He had skills(技能) he was sitting on! He may have lived the rest of his life as a no-name piano player in a no-name bar. But once he caught the chance, and found, by accident, that he could sing well, he went on working hard and became one of the best-known singers in the US. His name was Nat King Cole.

    You, too, have skills. You may not feel that your skills are great, but it may be better than you think. With hard work, most skills can be improved(提高).