题干

下列说法错误的有(   )

①化学反应除了生成新物质外,还伴随着能量的变化

②放热反应不需要加热就能发生

③需要加热才能发生的反应都是吸热反应

④化学反应放热还是吸热,可看生成物具有的总能量和反应物具有的总能量的相对大小

⑤绿色植物进行光合作用时,将太阳能转化为化学能“贮存”起来

⑥等量的氢气和氧气分别完全燃烧生 成气态水和液态水,前者放出的热量多.

A:2项

B:3项

C:4项

D:5项

上一题 下一题 0.0难度 选择题 更新时间:2020-02-06 04:10:57

答案(点此获取答案解析)

B

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阅读理解

    April is Financial Literacy Month,when Americans of all ages are encouraged to learn how to be smart about money.And this year,fifth­grade Rachel Kelly from Naperville,Illinois,is already at the head of her class.Kelly,11, won a nationwide contest called the Stock Market Game.

    Students who take part in the Stock Market Game,run by the SIFMA Foundation,a financial­education organization,pretend to buy stocks (股票) worth $100,000.Then they have to read financial news over several days to see if their investments would have gained money or lost money and write an article explaining their choices.

    “I  wanted  to  choose  a  company  that was well­known,” writes Kelly.“I thought about products that I see every day,so cars came to my mind.” Kelly picked the Japanese car company Honda Motors.“Honda Motor Company is the No.1 producer of motorcycles in the world and the fifth­largest producer of automobiles behind Toyota,Volkswagen,General Motors and Hyundai,” says Kelly.

    Honda makes many different kinds of cars,which Kelly thinks makes the company a safe investment.She explains that even if the cost of gas goes up,Honda has a good chance of staying in business because of the company's fuel­efficient cars,which run on less gas than most cars made today.

    “If one of their departments is not doing so well,it won't affect the overall company sales,” she writes.

    Because the stock Kelly picked performed well and her article was persuasive,Kelly won this year's contest.About 600,000 students from 4th to 12th grade competed.