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把在空气中久置的铝片5.0g投入盛有500mL 0.5mol•L1硫酸溶液的烧杯中,该铝片与硫酸反应产生氢气的速率与反应时间的关系可用如图曲线来表示,回答下列问题:

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同类题1

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资料1:图1中这只憨态可掬的大鸟叫渡渡鸟,可惜的是这种鸟已于1861年灭绝了.欧洲航海者的日记显示,在15世纪以前,生活在毛里求斯岛上的渡渡鸟随处可见.后来欧洲殖民者到达了毛里求斯岛,他们疯狂地猎捕肉味鲜美的渡渡鸟,加之殖民者带来的猪、狗、鼠等动物的影响,渡渡鸟灭绝j.渡渡鸟灭绝之后,岛上的大颅揽树便一蹶不振,日渐稀少,面临着灭绝的危险.这种树的果实果皮坚厚,种子很难萌发.渡渡鸟最喜欢吃大颅揽树的果实,果实经过渡渡鸟的消化道后,果皮变薄了.内部的种子才能正常萌发.

资料2:2014年5月30日,一位游客在山西省级自然保护区云顶山游览时,发现山顶上居然有人在搞大面积施工,山上大片植被惨遭破坏!(如图2中的“斑秃”部分)云顶山位于山西省娄烦和交城、方山三县交界处,距太原市100多公里.主峰海拔2708米,是吕梁山脉腹地高峰之一,因山势险峻,山顶直插云际而得名,被称为“山西的青藏高原”.云顶山中森林密布,古木参天,有野生种子植物936种.按照野生植物的主要经济用途分类,可将云顶山植物资源分为材用植物、药用植物、油脂植物、观赏植物、食用植物、有毒植物和蜜源植物7类,但就是这样一个自然保护区.却不知被什么人肆意“开垦”了!

同类题3

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    At a talk to some businessmen earlier today, one fellow asked me, “Would you give money to a homeless person, even when you know he's going to use it to buy alcohol?” I replied, “If all was giving was money, it'll be one thing. But for me, whenever I do give money, that's just the wrapping (包装纸) . The real gift is hidden inside – it's love. And l haven't ever found any reason to limit gifts of love.”

    By the end of the night, I decided to get some pizza. In front of me in line was a homeless-looking man. He was counting the few dollar bills in his hand, over and over again, until it was his turn to order. Just then, he told the young woman behind the counter, “I'll have the full cheese pizza.” “Full?” she countered. “It's really big.” she added, although what she really meant to say is that it'll be too expensive for him. “Yeah, the full.” “$18.65,” she submitted. The bills he was counting weren't going to make it. I wasn't intending to get the whole pizza for him. But thinking back to my conversation with the business man, l realized that money was really just the wrapping.

    I made my move. “Can you charge that pizza with my order?” I said to the cashier. “Really?” the homeless-looking man said. “Really?” the young woman behind the counter repeated. “Yes, really.” That disheveled (凌乱的) man and I had a sweet silent moment. To his silent question of why I was doing it, I added, “Just pay it forward for someone else.” And he said, “Well, you know what? I was actually treating these five homeless guys out there.” He was actually paying it forward, in the first place. What an unexpected fortune to get a chance to be a part of a man's act of kindness.

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