题目

25℃、101kPa条件下，在一个容积可变的密闭容器中加入一定体积的NO2气体发生反应2NO2N2O4，保持活塞位置不变。分别在t1、t2时刻迅速移动活塞位置并保持移动后的活塞位置不变，测定容器内气体压强变化如图所示。下列说法不正确的是A.B点N2O4的物质的量分数为97%B.H点对应的容器内气体颜色比E点的深C.C点的正、逆反应速率大小：v正＜v逆D.B、E两点的混合气体平均摩尔质量大小：M(B)＞M(E)阅读理解。     A friend of mine named Paul received an expensive ear from his brother as a Christmas present. On Christmas Eve when Paul came out of his office,a street urchin (顽童) was walking around the shining car."Is this your ear, Paul?"he asked. Paul answered,"Yes,my brother gave it to me for Christmas."The boy was surprised. "You mean your brother gave it to you and it didn't cost you nothing? Boy, I wish…"He hesitated. (犹豫)      Of course Paul knew what he was going to wish for. He was going to wish he had a brother like that. But what the boy said surprised Paul greatly.      "I wish," the boy went on,"that I could be a brother like that."Paul looked at the boy in surprise, then he said again, "Would you like to take a ride in my ear?"      "Oh, yes. I'd love that."      After a short ride,the boy turned and with his eyes shining, said,    "Paul, would you mind driving in front of my house?" Paul smiled a little.He thought he knew what the boy wanted. He wanted to show his neighbors that he could ride home in a big car.But Paul was wrong again."Will you stop where those two steps are?" the boy asked.      He ran up to the steps.Then in a short while Paul heard him coming back,but he was not coming fast. He will carrying his little crippled (残疾) brother.He sat him down on the step and pointed to the car.      "There she is, Buddy, just like I told you upstairs.His brother gave it to him for Christmas and it didn't cost him a cent (美分). And some day I'm going to give you one just like it…then you can see for yourself all the nice things in the Christmas window that I've been trying to tell you about."      Paul got out and lifted the boy to the front seat of his car. The shining-eyed older brother climbed in beside him and the three of them began an unforgettable holiday ride. 1. The street urchin was very surprised when ________. A. Paul received an expensive car B. Paul told him about the car C. he saw the shining car 2. From the story we Call see the urchin ________. A. wished to give his brother a car B. wanted Paul's brother to give him a car C. wished he could have a brother like Paul's 3. The urchin asked Paul to stop his car in flout of his house ________. A. to show his neighbors the big car B. to show he had a rich friend C. to tell his brother about his wish 4. We can infer (推断) from the story that ________. A. Paul couldn't understand the urchin B. the urchin had a deep love for his brother C. the urchin wished to have a rich brother 5. The best name of the story is ________. A. A Christmas Present B. A Street Urchin C. A Brother Like That