听力原文:W: Do you know? Tom failed to win that speech contest. M: Did he? I thought for sure he wouldn't. He worked so hard on it. W: Perhaps that's why he lost. They thought he was simply reciting. How does the man feel about the result?
【简答题】家庭厨房就是一个充盈的化学小世界,“柴米油盐酱醋糖”包含着许多化学内容: (1)家庭厨房中的“柴”趋向洁净,气态燃料有煤气、液化石油气,还有______等. (2)米、面的主要成分是淀粉,化学式为(C 6 H 10 O 5 )n,氢氧元素的质量比为______. (3)超市货架上的食盐品种丰富,有锌盐、钙盐、硒盐、加碘盐等等.这些食盐中含的锌、钙、硒、碘等是指______.(填:单质、原子或元素)...