题干

氢化钠(NaH)是一种白色的离子化合物,其中钠元素是+1价;氢化钠与水反应生成H2和NaOH.下列叙述中,不正确的是(   )

A:NaH的电子式为Na+:H﹣

B:NaH中氢元素的离子的电子层排布与氦原子的电子层排布相同

C:微粒半径H﹣<Li+

D:NaH与H2O反应时,水作氧化剂

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C

同类题1

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

      It's normal to wake briefly during the night. ____ But if you're waking up duringthe night and having trouble falling back asleep, the following tips may help.

     Stay out of your head. The key to getting back to sleep is continuing to prepareyour body for sleep, so remain in bed in a relaxed position. Hard as it may be,try not to stress over the fact that you're awake, because that very stress andanxiety encourage your body to stay awake. ____

____If you are finding it hard to fall back asleep, try a relaxation technique suchas visualization(想象),or deep breathing, which can be done without even getting out of bed. Remindyourself that although they're not a replacement for sleep, rest and relaxationstill help refresh your body.

    Do a quiet, non-stimulatingactivity. If you've been awake for more than 15 minutes, try getting out of bedand doing a quiet, non-stimulatingactivity, such as reading a book. Keep the lights dim so as not to think thatit's time to wake up. ____  A light snackmight relax you, but be careful not to eat so much that your body begins toexpect a meal at that time of the day.

____If you wake during the night feeling anxious about something, make a brief noteof it on paper and delay worrying about it until the next day when you arefresh and it will be easier to resolve.

a.Make relaxation your goal, not sleep.

b.Put off worries and troubles.

c.Use a flashlight to go to the bathroomat night.

d.In fact, a good sleeper won't evenremember it.

e.Also avoid screens of anykind—computers, TVs, cell phones, iPads.

f.You'll be much more productive andcreative after a good night's rest.

g.A good way to stay out of your head isto focus on the feeling in your body.

同类题5

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    I really love my job because I enjoy working with small children and like the challenges and awards from the job. I also think my work is important. There was a time when I thought I would never have that sort of career.

    I wasn't an excellent student because I didn't do much schoolwork. In my final term I started thinking what I might do and found I didn't have much to offer. I just accepted that I wasn't the type to have a career.

    I then found myself a job — looking after two little girls. It wasn't too bad at first. But the problems began when I agreed to live in so that I would be there if my boss had to go out for business in the evening. We agreed that if I had to work extra hours one week, she'd give me time off the next. But unfortunately, it didn't often work out. I was getting extremely tired and fed up, because I had too many late nights and early mornings with the children.

    One Sunday, I was in the park with the children, and met Megan who used to go to school with me. I told her about my situation. She suggested that I should do a course and get a qualification(资格证书)if I wanted to work with children. I didn't think I would be accepted because I didn't take many exams in school. She persuaded me to phone the local college and they were really helpful. My experience counted for a lot and I got on a part-time course. I had to leave my job with the family, and got work helping out at a kindergarten.

    Now I've got a full-time job there. I shall always be thankful to Megan. I wish I had known earlier that you could have a career, even if you aren't top of the class at school.