题目

一个圆锥的底面半径为2cm，高为6cm，在其中有一个高为xcm的内接圆柱， （1）画出此组合体的直观图，并求求圆锥的表面积； （2）当x 为何值时，圆柱侧面积最大？求出最大值。 答案： 解：(1)画出组合体的直观图        （2分）              （5分）  (2)设圆柱的底面半径为r，于是有：， （8分）    （10分） 所以，当x=3时，圆柱有最大值为6           （12分）I've loved my mother's desk since I was just tall enough to sit above the top of is mother sat writing letters. Standing by her chair, looking at the ink bottle, pens, and white paper, I thought that the act of writing must be a most wonderful thing in the world. Years later, during her final illness, mother kept different things for my sister and brother."But the desk," she said again "is for Elizabeth." I never saw her angry, never saw her cry. I knew she loved me; she showed it action. But as a young girl. I wanted to have heart-to-heart talks between mother and daughter. They never happened. And a gulf opened between us. I was "too emotional (易动感的)". But she lived "on the surface ". As years passed and I had my own family. I loved my mother and thanked her for our happy family. I wrote to her in careful words and asked her to let me know in any way she chose that she did forgive me. My hope turned to disappointment, then little interest and, finally peace ,it seemed that nothing happened. I couldn't be sure that the letter had even got to mother. I only knew that I had written it, and I could stop trying to make her into someone she was not. But the present of her desk told me, as she'd never been able to, that she was pleased that writing was my chosen work. I cleaned the desk carefully and found some papers inside a photo of my father and a one-page letter, folded and refolded many times. It was my letter. "In any way you choose, mother, you always chose the act that speaks louder than words."1.The writer began to love her mother's desk ______.A. after Mother died B. before she became a writerC. when she was a child D. when mother gave it to her2.The passage shows that ______A. mother was cold on the surface but kind in her heart to her daughterB. mother was too serious about her daughter in wordsC. mother cared much about her daughter in wordsD. mother wrote to her daughter in careful words3.The word "gulf" in the passage means ______A. deep understanding between the old the youngB. different ideas between mother and daughterC. free talks between mother and daughterD. part of the sea going far in land4.What's best title of the passage?A. My Letter to Mother B. Mother and ChildrenC. My Mother's Desk D. Talks between Mother and me 1.C 2.A 3.B 4.C 【解析】试题分析：本文是一篇记叙文。作者从小就喜欢母亲的书桌，她和母亲之间从未心与心的交谈，因此她们之间有代沟。成年后，作者给母亲写信希望她原谅她，但一直没有收到回信，但母亲在最后时刻把书桌留给了作者，使她深刻地感受到母亲虽然表面上很冷酷，可内心里却很体贴自己。短文表达了作者对母亲深情的爱和思念。 1.题意：作者 开始喜欢她母亲的桌子。...