题目

依据如图所示实验现象，关于二氧化碳的说法不正确的是A．密度比空气大 B．不能燃烧C．不支持燃烧 D．能使温度降到蜡烛的着火点以下  答案：D解析:略 More than 20,000 drivers and front seat passengers are killed or seriously injured each year. At a speed of only 30 miles per hour it is the same as falling from a third floor window. Wearing a seat belt saves lives; it reduces your chance of death or serious injury by more than half.Therefore drivers or front seat passengers over 14 most vehicles must wear a seat belt. If you do not, you could be fined up to $50. It will not be up to the drivers to make sure you wear your belt. But it will be the driver’s responsibility to make sure that children under 14 do not ride in the front unless they are wearing a seat belt of some kind.However, you do not have to wear a seat belt if you are reversing(倒退) your vehicle; or you are making a local delivery or collection using a special vehicle; or if you have a valid（正当的） medical certificate（证书）which excuses you from wearing it. Make sure these cases supply to you before you decide not to wear your seat belt. Remember you may be taken to court for not doing so, and you may be fined if you cannot prove to the court you have been excused from wearing.60. This passage is probably taken from ______.A. medical magazine    B. a legal documentC. a textbook    D. a government information booklet61. Wearing a seat belt in a vehicle ______.A. reduces road accidents by more than half B. reduces the death rate in traffic accidents C. saves lives while driving at a speed up to 30 miles per hour  D. saves more than 16,000 lives each year62. It is the driver’s responsibility to ______.A. make the front seat passenger wear a seat belt B. make the front seat children under 14 wear a seat beltC. stop children from riding in the front seat D. wear a seat belt each time he drives63. For some people, it may be better to ______.A. pay a fine rather than wear a seat belt   B. wear a seat belt for health reasonsC. (not to) wear seat belt for health reasons  D. get a valid medical certificate before wearing a seat belt