阅读理解。
Helping others makes me proud
I paid a visit to a church in Washington DC not long ago and got to go to a service (服务) for the
homeless.
When we arrived at the church, our fiends Roger and Nancy, who work in the church, gave us a
warm welcome and invited us inside. The priest (牧师) was standing in front of a screen and giving a
sermon (布道).
He told jokes and funny stories in his sermon. For the first time I realized church could be fun.
After that, we walked down to the hall where we were to serve the homeless. Two volunteers, Jason
and Sandra, were clearing the table and making dinner.
"We have been coming here each weekend for two years. "Sandra told me." It's really nice to help
the homeless people." She told me the church has been doing these services every week for many years.
When we finished setting the table and cooking dinner, Jason brought the homeless people to the
church. We served a big meal of potatoes, chicken,green beans and cake. We sat down at the table and
chatted with some of the homeless people.
One man told me: "People ask me: 'Is it difficult to be a homeless person?' and I say:
'I don't feel it's that hard. It doesn't matter if I'm homeless or not because I have this church and I have
people like you.' "Hearing these words from a homeless person, I felt prouder than I ever had before.
1. Where did the writer pay a visit?
A. A church in Washington.
B. A friends home.
C. A church in Washington DC.
D. We don't know.
2. The writer realized the church could be fun for the first time, because _______.
A. the writer's friends gave a warm welcome.
B. the priest was standing in front of the screen.
C. the writer's friends told jokes and funny stories.
D. the priest told jokes and funny stories in his sermon.
3. How many volunteers are mentioned in the passage?
A. Four.
B. Three.
C. Two.
D. One.
4. How often do they go to the church to help people?
A. once a month
B. Once a week.
C. Every two years
D. Every day
5. What did Jason do when the meal was finished?
A. He sat down at the table and enjoyed the meal.
B. He chatted with some:of the homeless people.
C. He brought the homeless people to the church.
D. He served the big meal to the homeless people.
，带入PH的计算公式可以得到
，整理得到
，
，
，要使反应后溶液的PH=7，那么H+和OH-恰好完全反应，二者的物质的量之比为1:1，当物质的量确定是浓度和体积成反比，根据浓度之比为1:10，所以体积之比为10:1，答案选B.