题目

如图，绝缘平板S放在水平地面上，S与水平面间的动摩擦因数μ＝0.4。两足够大的平行金属板P、Q通过绝缘撑架相连，Q板固定在平板S上，P、Q间存在竖直向上的匀强电场，整个装置总质量M＝0.48kg ，P、Q间距为d＝1m，P板的中央有一小孔。给装置某一初速度，装置向右运动。现有一质量m＝0.04kg、电量q＝1´10-4C的小球，从离P板高h＝1.25m处静止下落，恰好能进入孔内。小球进入电场时，装置的速度为v1＝5m/s。小球进入电场后，恰能运动到Q板且不与Q板接触。It is six o’clock in the morning. You are asleep in my left arm and I am learning the art of one-handed typing. Your mother, more tired yet more happy than I’ve ever known her, is sound asleep in the room next door. When you’re older we’ll tell you that you were born in Hong Kong in the lunar year of the pig. “It's a boy, so lucky,” our neighbours told us. They said you were the first baby to be born in the block this year. This, they told us, was good Feng Shui, in other words, a positive sign. Naturally your mother and I were only too happy to believe that. Your coming has turned me upside down and inside out. I am pained by the memory of each suffering child I have come across on my journeys as a journalist. To tell you the truth, it’s nearly too much for me to even think of the children being hurt and abused and killed. Last October, in Afghanistan, when you were growing inside your mother, I met Sharja, aged twelve, motherless, fatherless, guiding me through the grey ruins of her home. Everything was gone, she told me. There is another memory of Rwanda, and the churchyard where I found a mother and her three young children huddled(蜷缩) together where they’d been beaten to death. The children had died holding on to their mother. Daniel, these memories explain some of the protectiveness I feel for you, and the occasional moments of blind terror when I imagine anything bad happening to you. 【小题1】We can see that this text is written to ________.A．the author’s wifeB．the author’s neighbourC．DanielD．a suffering child【小题2】The author mentions some of his painful memories because ________.A．he wants his son to care for othersB．he feels more pain thinking about them as a fatherC．he hopes to forget the tragedies he witnessedD．his experience has affected his mental health【小题3】The underlined word “blind” in the last paragraph means ________. A．unable to seeB．meaningfulC．not clearD．not based on reason【小题4】Which of the following words best describes the author’s feeling when typing this text?A．Relieved.B．Regretful.C．Loving.D．Calm.