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《论语》十二章（节选）

    子日：“学而时习之，不亦说乎？有朋自远方来，不亦乐乎？人不知而不愠，不亦君子乎？”（《学而》）

    曾子日：“吾日三省吾身：为人谋而不忠乎？与朋友交而不信乎？传不习乎？”（《学而》）

    子日：“吾十有五而志于学，三十而立，四十而不惑，五十而知天命，六十而耳顺，七十而从心所欲，不逾矩。”（《为政》）

    子曰：“贤哉，回也!一箪食，一瓢饮，在陋巷，人不堪其忧，回也不改其乐。贤哉，回也!”（《雍也》）

    子日：“三人行，必有我师焉。择其善者而从之，其不善者而改之。”（《述而》）

Dear Grandma and Grandpa,

    I miss you so much. Thank you for the new bike! I'm so excited! How did you know 1 is my favorite color?

    When I first 2 the box under the Christmas tree, I didn't know what it was. I thought it was 3 small to hold a bike. Then when I opened it, I saw that the bike was in small pieces. That's 4 the box was small!

    Dad and I put them 5 the next day. It was a lot of fun. 6 we finished, I got on the blue bike and 7 around the town. My old bike was too small for me. This one is just 8. It looks great, too! All 9 friends want one like this now. Dad said that I could take my 10 when we go to visit you in the spring. I can't wait.

Yours,

David

尿液的形成主要包括肾小球的____和肾小管的____两个过程。