题干

硝酸钠溶液中混有Mg2+、Ba2+、Ag+三种金属离子,现用NaOH、Na2SO4、NaCl三种试剂使它们成为沉淀分离出来,要求每加一种试剂,滤出一种沉淀,最后达到除去杂质的目的,则所加试剂正确的是(   )

A:NaCl、Na2SO4、NaOH

B:Na2SO4、NaOH、NaCl

C: NaOH、 Na2SO4、NaCl

D:NaOH、NaCl、Na2SO4

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A

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    I now work 40 hours a week at a weather company and I love it Compared to when I became a mom, I don't feel bad about being away from my three kids. When I had my first child, I was a busy manager. My husband had a part-time job and cared for her the rest of the time. Once I became pregnant with my second kid, I quit my job to focus fully on writing.

    At first I felt like I was living the dream. I was a work-from-home mom who never had to be away from my children. But working from home can end up being more stressful than working full-time or being a stay-at-home mom.because you're frequently exhausted between work, keeping house and telling sweet faces you don't have time to play. Ever tried writing an article with a baby screaming? It was awful.

    I was so stressed that I eventually started taking my kids to 8 day care center a couple of days a week. The whole reason I worked so hard to be able to write for a living was to be at home with my kids and here I was taking them to a day care center.I thought I was a failure then.

    Over the past five years of being a freelancer(自由作家), I've realized a couple of things. As I wrote six months  ago, "I though I felt bad leaving my daughter for ten hours a day but now she is old enough to ask me to read her a story .Try telling your kid no, 20 times a day. It's cruel. You end up feeling worse for having to ignore them." I also realize not socializing with people weren't good for my mental well-being.

    Not only that, but I can now show my kids that Mom is important and has a job at a flashy office building, something they didn't realize when1 sat around in yoga pants typing on my computer all day long.