剪辫、易服和停止缠足使我国社会习俗开始有较大改观，这主要应该归功于（     ）

    A group of students at Sunshine School are holding a charity sale to raise money to help their classmate Lisa. Lisa had cerebral palsy (大脑性瘫痪) when she was a baby. People who have cerebral palsy have trouble walking. Although Lisa has to use a wheelchair (轮椅) to help her get around, she never gives up.

    "Lisa has the chance of standing up, but she needs an operation (手术)," Lisa's doctor said.

    "I never thought that I could stand up one day. Actually the news is surprising for me. However, when I see my parents are worried about the cost of the operation, I am sad. I don't mind if I can't stand up," Lisa said. "Now my classmates and some other kind people are helping me. I am really thankful."

    "While helping Lisa, we can also learn a lot. We have learned how to cook cookies (曲奇饼) and how to sell them," Betty, one of Lisa's classmates said. "Now we know making money is not easy, so we won't waste money anymore."

    Alex, a boy in Lisa's class, told a reporter that they could raise about $100 every day. "We have raised about $2,100 so far. We hope we will raise more money for Lisa's operation," he said.

设直线（k+1）x+（k+2）y﹣2=0与两坐标轴围成的三角形面积为S_k，则S₁+S₂+…+S₁₀=____ 

阅读下面短文，从每题所给的A、B、C、D四个选项中选出最佳选项。

    Do you want to become an astronaut? If you want to be one of the few people to experience the thrill of lift-off(发射), see the Earth from on high and float(漂浮) in a spacecraft, then how do you go about it?

First, you must really want to become an astronaut as it takes many years of study and work before you even begin your astronaut training. Most astronauts begin when they are between 27 and 37. Second, you need to be clever enough to attend a university to study engineering, medicine or one of the sciences. Many astronauts also learn to be pilots in their country's air force(空军). Third, astronauts come from many different countries, so they need to speak English. Then they can all talk to one another. Fourth, you must be healthy as astronaut training can be very tiring. Lastly, on a spacecraft, astronauts live and work in a very small space, so you need to get on well with people.

    Are you still interested? If so, maybe you will become one of the men or women that orbit the Earth in a spacecraft, walk in space or visit Mars. See you in space!