我国法律规定，公安机关对犯罪嫌疑人的拘押讯问时间一般不超过24小时，严禁刑讯逼供。监狱服刑人员在进行必要劳动时，安排适当休息，有劳动安全卫生防护用品，不得侮辱、体罚、打骂服刑人员等。这都表明
①我国尊重和保障人权             
②任何公民的合法权利都受到法律保护
③我国公民政治权利和自由是真实、不受限制的     
④我国坚持公民权利和义务统一

如图，A处通入Cl₂，关闭B阀时，C处的红布看不到明显现象；当打开B阀后，C处红布条逐渐褪色．则D瓶中装的是（    ）

    Here comes the last term of Junior 3. Terrible! The big exam is coming in less than two months. You still have a lot to do. How will you spend it? We invited three students to share their stories.
Dou Yi, 15,Beijing
    My chemistry  used to be poor in the past. I got scores of around 40 on every test. During the last term, I decide to beat chemistry. I will start to work hard. In class I take every possible note. After school, I spend most of my time studying chemistry. My parents also ask their friend, a chemistry teacher, to help me . Finally in the latest exam, I got 65! How happy I am!
Wang Zhaolin, 16, Chongqing
    My foot got hurt a week before the big PE exam . Luckily, I recovered（康复） in time. For PE , all you need is to practice. Sports can also help you relax. Be careful not to get hurt as I did.
Wang Feixuan, 15, Xi'an
    My experience is that for Junior3, every minute of the last term is important. Don't waste any of them. I try to remember English words while waiting in line to get my lunch. I read textbooks on the bus to and from school. I work hard at home and sometimes stay up late studying. Want to have fun? Leave it for the summer holiday after the big exam!

“奶茶妹妹”对某时间段的奶茶销售量及其价格进行调查，统计出售价x元和销售量y杯之间的一组数据如下表所示：

价格x	5	5.5	6.5	7
销售量y	12	10	6	4

通过分析，发现销售量y对奶茶的价格x具有线性相关关系．

（Ⅰ）求销售量y对奶茶的价格x的回归直线方程；

（Ⅱ）欲使销售量为13杯，则价格应定为多少？

注：在回归直线y= $\hat{b}x+\hat{a}$ 中， $\hat{b}=\frac{{{\displaystyle \sum }}_{i=1}^n{x}_i{y}_i-n\overline{x}\overline{y}}{{{\displaystyle \sum }}_{i=1}^n{x}_i^2-n{\overline{x}}^2}$ ， $\hat{a}$ = $\overline{y}$ ﹣ $\hat{b}\overline{x}$ ． ${\displaystyle \sum }_{i=1}^4{x}_i{}^2=5^2+{5.5}^2+{6.5}^2+7^2$ =146.5．

如图所示的几何体中，四边形ABCD为梯形，AD∥BC，AB⊥平面BEC，EC⊥CB，已知BC=2AD=2AB=2．