《辛丑条约》签订后，一本启蒙读物这样写道：“这中国，哪一点我还有份；这朝廷，原是一个名存实亡！替洋人，做一个守土长官…”下列《辛丑条约》的条款中，最能体现“替洋人，做一个守土长官”观点的是（　　）

    We call the Chinese New Year the Spring Festival. There is a name for each Chinese year. We may call it the year of the Dog, the year of the Monkey or the year of the Pig, etc. And this year is the year of the Snake.

    Before New Year's Day, people are busy shopping and cleaning their houses. On New Year's Eve, there is a big family dinner. After dinner all the family stay up late to welcome the New Year. On the first day of the New Year, people put on their new clothes and go to visit their friends and relatives. They say “Good luck” and some other greetings (问候) to each other. People usually have a very good time during the festival.

（2015•菏泽）太阳能是人类取之不尽、用之不竭的、清洁的____ 再生能源（填“可”或“不可”）．“阳光动力2号”飞机运行中的全部能耗都是利用太阳能电池板为其提供的，为确保“阳光动力2号”飞机着陆时的能见度，飞机上安装了16盏LED着陆灯，每盏着陆灯的功率只有10W（其光照强度相当于200W的白炽灯）．如果着陆过程需要10分钟，则每盏LED着陆灯着陆过程消耗的电功是　____ 　J．

下列变化中，必须加入氧化剂才能发生的是（  ）  

函数y= $\sqrt{\sin x-\frac{1}{2}}$ 的定义域是____．