题目

下列反应中，通入的气体只作氧化剂的是 A．SO2通入H2S溶液中              B．Cl2通入NaOH溶液中 C．SO2通入KOH溶液中             D．SO2通入氯水中 答案：A 解析: 略Jim couldn’t understand how the machine worked until his friends____ how to use itA.promisedB.explainedC.thoughtD.heard