题目

某化学小组同学用下图所示的三套装置进行二氧化碳性质的探究。 已知：15℃、101kPa下，1体积水约能溶解1体积的二氧化碳。  A                    B                  C （1）A和B中的塑料瓶容积相同，且充满CO2。将A的瓶盖打开，加入体积约为塑料瓶容积1/3的蒸馏水，旋紧瓶盖后充分振荡；向B中注入等体积的蒸馏水，充分振荡。 ①A中观察到的实验现象是_____。 ②B中塑料瓶无明显变化，其原因是_____。 （2）C装置用传感器测量瓶内气I am a single working mother and going to college for a better life for my three-year-old child and myself. I am taking a nurse course called “Urban Community（社区）”. We were asked to do a major project on problems in urban communities. I chose the topic “Homeless”.Each day I would walk down the streets of the homeless and offer them something to drink and to eat. I know it’s tough to survive on the streets. Last night I ran into a group of 30 kids who were living on the streets in New York. My heart went out to them and I just wanted to cry. But I had to be strong.I asked about their families and if they contacted them to let them know they were alive. Most of them said, “NO!” They all looked like a happy family and they took care of one another. I tried to persuade them to get help and to contact their families but they did not want to. I did not want to make them to do it as they had their own reasons.All these kids were very respectful. None of them was high on drugs nor were they drinking. Some of them enjoyed reading and writing. Some of them enjoyed skateboarding, dancing and playing music.One girl asked me if I could give her a hug and I did so. She started to cry and said, “Thank you for not treating us as freaks（怪人）like everyone else does. People don’t realize that we all have our own problems and some are worse than others.” She told me that her stepfather （继父） was extremely mean to her and her mother did not believe her. She ran away. Her street name was Little Mary.They were good kids just trying to make ends meet. I told them that I didn’t have much to offer because I was a single mother just making ends meet. I had offered them sandwiches and drinks. They were so happy to have something to eat and told me that I couldn’t change the world but at least there was someone who really cared.1.The author is _______.A. a homeless mother with a three-year-old kidB. a single mother who attends college in New YorkC. a teacher who teaches the “Urban Community” courseD. a full-time housewife with a three-year-old kid2.What does “My heart went out to them” in Paragraph 2 mean?A. My heart was taken away by them.B. I wanted to hug themC. I felt sympathy for them D. I fell in love with them3.What kind of feeling did the author show when she failed to persuade the children to contact their families?A. Sorrow B. Anxiety C. Anger D. Understanding4.Little Mary left home and became a wanderer because ________.A. her stepfather didn’t want to live with herB. her stepfather treated her so badly that she was injuredC. her mother treated her so badly that she felt hurtD. her mother didn’t believe her and her stepfather treated her badly.5.What’s the best title for this passage?A. A Story of a Single MotherB. Care for the Homeless KidsC. An Urban CommunityD. How to Survive on the Streets