题目

Read the following text and choose the most suitable heading from the list A--F for each paragraph. There is one extra heading which you do not need. （考生注意答题卡上的题号要与本题填涂时一致，从76题涂卡） A. TV’s Influence onChildren’s Life B. Argument AgainstViolence on TV C. TV’s Influence onPeople’s Leisure Activities D. The Importance ofViolence in Real Life E. Attractions ofViolence on TV F.  TV’s Power _________ Television has probably been the most powerful medium in shaping the new community. The electronic community gives us our mutual friends, (5分)化学为交通运输做出很多贡献。请回答下列问题：（1）汽车在行驶过程中的能量转化是__________________________；（2）飞机外壳用的主要材料是硬铝，它属于_______(填序号)；A．合成材料    B．金属材料    C．复合材料 （3）载人航天飞船所用固体燃料是铝粉和高氯酸铵(NH4ClO4)的混合物。发射时，点燃铝粉产生大量的热，达到高温，引起高氯酸铵发生分解，产生空气中含量最多的两种气体、一种常见的液态氧化物和氯气。写出高氯酸铵分解的化学方程式_____________________，该反应前后氮元素的化合价变化为_________。