题目

现有氧气、水、氯酸钾、红磷、二氧化锰，请选择其中的一种或两种作为反应物，按下列要求写出化学方程式： （1）分解反应（写两个） ； ． （2）化合反应（写一个） ； （3）氧化反应 答案：【考点】书写化学方程式；反应类型的判定． 【专题】化学用语和质量守恒定律． 【分析】首先根据反应原理找出反应物、生成物、反应条件，根据化学方程式的书写方法、步骤进行书写即可． 【解答】解：（1）水在通电条件下分解生成氢气和氧气，符合“一变多”的特点，属于分解反应；氯酸钾在完形填空。George and Betty didn’t have much money, but they wanted to buy a car. Betty didn’t have a ________ , so she was always finding ways to save money.She ________ vegetables in her garden so that she wouldn’t have to buy any. She made sandwiches for George to ________ to work so that he wouldn’t have to buy his lunch. Every day George took the bus to go to work and go home. It was not a long trip ________ the bus was slow because of the traffic. One day, the traffic was even ________ than usual. “I could run faster than this bus!” thought George.The next day ________ work he decided to have a try. He went to the bus stop but didn’t take the bus. He ran along beside it on the sidewalk. He had to run quite fast to ________ the bus. He arrived home. Betty was ________to see him panting (喘气). She was worried. “What’s the matter?” she asked. “I ran along beside the bus,” said George. “I saved two dollars and fifty cents without paying the fare.” He thought it would make Betty ________ , but it didn’t. “________ didn’t you run beside a taxi?” she said. “You would have saved six dollars!”1.A. work B. job C. child D. house2.A. grew B. gave C. bought D. knew3.A. make B. carry C. bring D. take4.A. or B. and C. but D. so5.A. larger B. bigger C. worse D. better6.A. after B. before C. finished D. began7.A. get out of B. get along with C. come up with D. catch up with8.A. excited B. surprised C. interested D. bored9.A. tired B. sad C. clean D. happy10.A. When B. What C. Why D. Where