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理想实验是物理发展过程中的一种重要的研究方法,伽利略曾设想了一个理想实验,如图所示(图中两个斜面底部均用一小段光滑圆弧连接),下列是该实验中的一些事实和推论

A.如果没有摩擦,小球将上升到原来释放时的高度

B.减小第二个斜面的倾角,小球在这斜面上仍然能达到原来的高度

C.继续减小第二个斜面的倾角,最后使它成为水平面,小球沿水平面做匀速直线运动

D.两个对接的斜面,让静止的小球沿一个斜面滚下,小球将滚上另一个斜面

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阅读下面短文,掌握大意,然后从1-20各题所给的四个选项(A、B、C和D)中,选出最佳答案。

        My husband, Bob, died in January 2004. His death was unexpected as well. I 1 condolences(哀悼)from people I hadn't heard from in years: letters, cards, flowers, calls, and visits. I took a bad knock with 2. I was so struggling to3the whys and hows of this terrible thing that had happened to my family, knowing in my heart that there really were no 4. It's just all so sad.

        One message5me deeply. I received a letter from my best friend from sixth6 through high school. We had drifted somewhat since 7 in 1959, as she stayed in our home town and I did not. 8 it was the kind of friendship that could quickly resume even if we9touch for five or ten years.

        Her husband, Peter, had died perhaps 20 years ago at a young age, 10her with deep sorrow and heavy 11: finding a job and raising three young children. She and Pete, 12 Bob and I, had shared one of those rare, close, "love-of-your-life-you-can-never-forget" 13.

        In her letter she 14 an anecdote about my mother who had passed away years ago. She wrote, "When Pete died, your dear mother 15me and said, 'Trudy, I don't know what to say...so I'll just say I love you.'"

        She closed her letter to me repeating my mother's words of so long16, "Bonnie, I don't know what to say...so I'll just say I love you."

        I felt I 17 almost hear my mother speaking to me now. What a 18 message of sympathy! How dear of my friend to cherish it all those years and then 19 it on to me.I love you. 20 words. A gift. A legacy(遗赠物).