题目

Dear Mr Perkins,        We would like to introduce ourselves. Our company was organized only two years ago. But we are now one of the largest boat companies in California. As you know, your son bought a boat from us recently, and I think you know how pleased he is with our product. Also, John Webb, one of your son’s friend’s has bought a boat from us and, we understand, Is very happy with his boat. We are always happy to know that our customers are satisfied.        We are writing to you now because, as you know, your son has decided to buy a larger boat, and we will n建立一个适当的模型来反映和代替客观对象，可以帮助我们认识和理解观察不到的化学反应．已知某两种物质在光照条件下能发生化学反应，其微观模型示意图如图，图中相同小球代表同种原子，原子间的短线代表原子的结合．下列从图示获得的信息中不正确的是（　　） A、该反应中共有三种元素B、图中反应物都是化合物C、该反应的本质是原子的重新组合D、该反应前后分子的种类发生了改变