题干

从一个细胞到青春洋溢的初中生,生命给了我太多的惊奇。

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同类题3

阅读说明文,完成小题
“种”出石油
①据科学家粗略估算,全球绿色植物每年产生的碳氢化合物可达300亿吨以上,只要将这些植物进行高压、高温加工,就能够制造出和石油成分相近的产品。目前。全球绿色植物储存的能量,大约相当于8万亿吨煤或8∞亿吨石油。可以说,植物是一座巨大的储油库。
②科学家研究发现,可用于制造石油的植物品种很多,不少乔木、灌木、海藻等含有极为可观的天然炼油物质。美国科学家选用了千余种最富生产能力的水藻进行实验,从其体内提取类脂化合物以化学的方法进行处理,从而转变成汽油和柴油。前苏联的科学家经过引导性的实验进一步证实,从锯末中也可以提炼出人造石油,这种植物能源比传统的石油和煤具有更多的优越性。首先,它便于就地生产利用,省却了远距离输送,因而成本比较低廉;其次,植物能源在燃烧过程中,一般不会形成有害物质,它所产生的二氧化碳也易于被植物吸收,对保护生态环境非常有利。
③众所周知,石油是多种碳氢化合物组成的混合物,许多植物也可直接产生碳氢化合物。倘若能够以适当的方法把这些碳氢化合物提取出来,我们就可以得到所谓的产绿色石油”。诺贝尔化学奖得主、美国的卡尔文教授,在一个人工石油植物种植场,种植了一种名叫“尤加利”的树木。这种树木的茎和种子中均舍有这种可燃物质,1000平方米土地每年产5绿色石油,每桶成本仅20美元,而当时每桶石油的价格是30美元。他的成功,推动了全球的石油植物研究。
④资料表明,美国现已拥有一个上百万平方米的能源植物速生林,英国已批准兴建一个石油植物园,瑞士已经制定出一个利用植物石油取代全国半数石油消耗量的计划。可以说,用不了多久,人类将“种”出石油

同类题5

阅读理解

    Jonathan Cranwell sat on a hard bench behind the long narrow desk and watched the flies fly lazily in the sun. The drone of the younger boys reading letters and the older boys reciting Latin verbs made him sleepy. Jonathan had to force his eyes to stay open. He wanted to learn something new!

    He looked up at the schoolmaster's high desk in the front of the room. The new teacher was from Harvard College. Jonathan's father had been impressed with him. The boys had already had several other teachers, but none of them seemed to inspire Jonathan. So far, there was nothing to show that this one was special , though he'd only been there two days.

    “It's too hot to sit and memorize lessons,” the schoolmaster said. “We'll move outdoors for the next part of our lesson.” He led the group of boys into the schoolyard. “You younger boys, dig for grubs and beetles ( 幼虫和甲虫). Count their feet. See if you can describe their shells”

    Jonathan watched the teacher surrounded by laughing young students. No one had ever used the schoolyard itself for a classroom. “What next ?” he thought. He didn't have time to think about the younger boys, for he was running after butterflies and dragonflies himself.

    Jonathan and his friends liked this new way of learning.

    “It will be a clear night tonight. Go outside and look at the sky,” said the schoolmaster. “Look at the stars and notice their brightness and the patterns they make. These patterns have names from Greek mythology(神话), names like Orion, Aries, and others. Tomorrow we will learn about the ancient stories on them.”

    “How is the new schoolmaster ?” asked Jonathan's father that evening, when Jonathan announced he was going out to look at the sky.

    “He's different from any other schoolmaster we've had,” Jonathan admitted. “He seems interested in everything around him, and he wants us to be curious too. He even used the schoolyard as a classroom!”

    “So Mr. John Adams and his new ways make school useful to you after all,” joked Jonathan's father.

    “I believe he has,” said Jonathan. “I know I won't forget the lessons he has taught us!”