题目

When the population of the port town began to suffer from poisoning（中毒）, the police came to find the cause of the poison. They thought someone was poisoning the people on purpose but no one knew how it was possible. Soon people took the position that the pork was poisoned. It was a popular food everyone ate and it could have possibly made everyone sick. Anyone who had possession of pork would throw it out. Even the poorest of the poor wouldn’t eat pork. Signs were posted on poles and letters were sent to everyone to warn people of the pork. Shortly afterwards, even policemen 用文字或化学式表示下列符合要求的反应式，并指出反应的基本类型（“化合”或“分解”）：（1）铁丝在氧气中燃烧______________________，_________反应；（2）水通电后生成氢气和氧气　___________________；_________反应；（3）甲烷（CH4）燃烧生成二氧化碳和水______________________________．