科学家最近研制出一种以锶做钟摆的钟，它是世界上最精确的钟，锶的原子结构示意图及在元素周期表中的某些信息如图所示，下列说法正确的是（　　）

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归纳法是高中化学学习常用的方法之一，某化学研究性学习小组在学习了《化学反应原理》后作出了如下的归纳总结：归纳正确的是

①对已建立化学平衡的某可逆反应，当改变条件使化学平衡向正反应方向移动时，生成物的产量一定增加

②常温下，pH=3的醋酸溶液与pH=11的NaOH溶液等体积混合后形成溶液a，等浓度的盐酸与NaOH溶液等体积混合后x形成溶液b，水的电离程度a＞b．

③常温下，AgCl在同物质的量浓度的氨水和NaCl溶液中的溶解度比较，前者大．

④若将适量CO₂ 通入0.1mol•L^﹣1 Na₂CO₃溶液中至溶液恰好呈中性，则溶液中（不考虑溶液体积变化）  2c（CO₃^2﹣）+c（HCO₃^ˉ）=0.1mol•L^﹣1

⑤常温下，已知醋酸电离平衡常数为Ka；醋酸根水解平衡常数为Kh；水的离子积为K_w；则有：K_a•K_h=K_w（　　）

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    Looking good can matter a lot when you are a teenager. Of course the budget(财政） matters a lot, too. Luckily, fashion trends (流行趋势) in the UK mean that getting the right image doesn't have to cost the earth. Here's a quick guide to which looks are hot this year.

    For girls, the 70s are back. Wide-legged jeans, platform shoes and skirts that reach the feet are again in fashion among UK teens, topped off with colored, shining eyeshadow. Girls can have fun mixing and matching bright shades. Colors like pink, orange and light yellow-green are all perfectly fit. Shorts and mini-skirts are still popular in cold weather. By wearing a pair of tights underneath ( 在..底下), girls can stay warm as well as fashionable in the winter.

    How about boys? To look lively, fans of skateboards and snowboards can dress in skinny jeans accompanied by a T-shirt topped off with a baseball cap or a woolen hat. Music is often an inspiration for fashion, and hip-hop music fans like to dress in baggy jeans, T-shirts, baseball caps and sneakers. For those who can afford it, designer clothing is a must, especially if the logo is showing.