题干

天然气作为燃料已进入千家万户。小聪在帮助父母烧菜时想到:天然气燃烧的产物是什么呢?带着这一问题,小聪和同学一起进行了如下的探究。

上一题 下一题 0.0难度 选择题 更新时间:2014-06-30 08:47:43

答案(点此获取答案解析)

同类题1

阅读下面文言文,回答问题。

    王翦者,频阳东乡人也。少而好兵,事秦始皇。秦始皇既灭三晋,走燕王,而数破荆师。秦将李信者,年少壮勇,尝兵数千逐燕太子丹至于衍水中,卒破得丹,始皇以为贤勇。于是始皇问李信:“吾欲攻取荆,于将军度用几何人而足?”李信曰:“不过用二十万人。”始皇问王翦,王翦曰:“非六十万人不可。”始皇曰:“王将军老矣,何怯也!李将军果势壮勇,其言是也。”遂使李信及蒙恬将二十万南伐荆。王翦言不用,因病,归老于频阳。李信攻平与,蒙恬攻寝,大破荆军。信又攻鄢郡,破之,于是引兵而西,与蒙恬会城父。荆人因随之,三日三夜不顿舍,大破李信军,入两壁,杀七都尉,秦军走。

    始皇闻之,大怒,自驰频阳,见谢王翦曰:“寡人以不用将军计,李信果秦军。今闻荆兵日进而西,将军虽病,独忍弃寡人乎!”王翦谢曰:“老臣罢病悖乱,唯大王更择贤将。”始皇谢曰:“已矣,将军勿复言!”王翦曰:“大王必不得已用臣,非六十万人不可。”始皇曰:“唯听将军计耳。”于是王翦将兵六十万人,始皇自送至灞上。王翦行,请美田宅园池甚众。始皇曰:“将军行矣,何忧贫乎?”王翦曰:“为大王将,有功终不得封侯,故及大王之向臣,臣亦及时以请园池为子孙业耳。”始皇大笑。王翦既至关,使使还请善田者五辈。或曰:“将军之乞贷,亦已甚矣。”王翦曰:“不然。夫秦王怚而不信人。今空秦国甲士而专委于我,我不多请田宅为子孙业以自坚,顾令秦王坐而疑我邪?”

    王翦果代李信击荆。荆闻王翦益军而来,乃悉国中兵以拒秦。王翦至,坚壁而守之,不肯战。荆兵数出挑战,终不出。王翦日休士洗沐,而善饮食抚循之,亲与士卒同食。久之,王翦使人问军中戏乎?对曰:“方投石超距。”于是王翦曰:“士卒可用矣。”荆数挑战而秦不出,乃引而东。翦因举兵追之,令壮士击,大破荆军。至蕲南,杀其将军项燕,荆兵遂败走。秦因乘胜略定荆地城邑。岁余,虏荆王负刍,竟平荆地为郡县。因南征百越之君。而王翦子王贲,与李信破定燕、齐地。

    秦始皇二十六年,尽并天下,王氏、蒙氏功为多,名施於后世。

(节选自《史记•白起王翦列传》)

注释:①怚:通“粗”,粗疏,鲁②超距:跳跃,古代的一种游戏,用于习武。

同类题5

阅读理解

    Sitting on the sofa in her family's Michigan home in 2009, looking through the Guinness World Records, 10 year-old Winter Vinecki was surprised to find that the record for the youngest person to complete a marathon on every continent was held by a 27-year-old man. “I can beat that,” she declared. “For Dad. ” And she had every reason to believe she could.

    A natural athlete since the age of 5, Winter had been running together with her mom and uncle, both athletes, and competing in races across the country. Soon, her name was appearing in national competitions. Trophies (奖牌) lined her walls.

    But in 2008, at the age of 9, Winter stopped racing for medals. In May of that year, her father found out he had caught a rare cancer. To raise awareness and funds to fight the disease. Winter started an organization called I earn Winter. Just 10 months after his diagnosis, her father passed away.

    Over the next three years, Winter came first in 20 of the 37 races in which she competed, including four Junior Olympics Cross Country Championships. Along the way, she raised over $ 400,000 to help find a cure for cancer.

    Now 14, Winter is working on her world record to win her cause a place in the Guinness World Records. She recently completed her first marathon in Eugene, Oregon, a race normally limited to runners over 16, finishing in an amazing 3:45:04. “I'm used to racing with adults, and I think it's kind of fun to race past them,” said Winter before the race.

    With six continents to go, Winter has just begun a journey that will take her two years. “Every time I step to a starting line,” Winter says, “I have one thought in mind: keeping my dad's spirit alive.”