题干

下列说法中,正确的一组是(  )
①两种元素构成的共价化合物分子中的化学键都是极性键
②两种非金属元素原子间形成的化学键都是极性键
③含有极性键的化合物分子一定不含非极性键
④只要是离子化合物,其熔点就比共价化合物的熔点高
⑤离子化合物中含有离子键
⑥分子晶体中的分子不含有离子键
⑦分子晶体中的分子内一定有共价键
⑧原子晶体中一定有非极性共价键

A:②⑤⑥⑦

B:①②③⑤⑥

C:②⑤⑥

D:②③⑤⑥⑦

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C

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    I've always been a very anxious person—easily worried and stressed. And I've always been losing things.

    I'm not sure what exactly 1 my desire to attempt a more organized lifestyle. I started to attempt to be less 2and more organized. Instead of cleaning my room twice a year, I 3to do it about 4-6 times a year.

    Over a couple of years I started cleaning my room more, and I even 4using a planner on a daily basis: It took years to institute these actions into habits, 5I wasn't aiming for habits. I was simply trying to be a little 6—a little bit at a time.

    After I 7multiple outfits(装束) at home, 8leaving clothes on my bed and shoes on the floor, I put everything away before going out. After cooking and eating, I put everything in the dishwasher or wash it by hand. Each of these tasks only takes a few minutes. And not only does this 9immediate clutter(杂乱), but it's also much 10to deal with one mess at a time rather than leaving it all to turn into a giant mess. Organization creates ease, and ease creates organization, both of which 11to lower levels of stress and anxiety! And spending less time feeling 12means having more time to be happy, productive and present.

    Since I began intentionally being more organized, I find I have more 13to adopt other new habits to maintain(保持) and strengthen a calmer and cleaner lifestyle. Good habits result in more good habits, which help to create a better and happier you.

    If you find yourself worried, stressed or anxious beyond your control, then 14what you can—your 15. Create a comfortable, clean and calm space where you can escape from the outside world, and it doesn't have to be all at once.