题干

同温同压下两个容积相等的贮气瓶,一个装有C2H4,另一个装有C2H2和C2H4的混合气体,两瓶内的气体一定具有相同的           

A:碳原子数

B:原子总数

C:质量

D:密度

上一题 下一题 0.0难度 选择题 更新时间:2019-03-05 01:03:35

答案(点此获取答案解析)

A

同类题3

任务型阅读

    To forgive is a virtue, but no one has ever said it is easy. When someone has deeply hurt you, it can be extremely difficult to let go of your hate. However, forgiveness is possible, and it can be surprisingly beneficial to your physical and mental health. People who forgive show less sadness, anger and stress and more hopefulness, according to a recent research.

    ____Try the following steps:

    Calm yourself. ____You can take a couple of breaths and think of something that gives you pleasure: a beautiful scene in nature, or someone you love. Don't wait for an apology. Many times the person who hurt you does not intend to apologize. They may have wanted to hurt you or they just don't see things the same way. ____ Keep in mind that forgiveness does not necessarily mean becoming friends again with the person who upset you.

    Take the control away from your offender(冒犯者). Rethinking about your hurt gives power to the person who causes you pain. Instead of focusing on your wounded feelings, learn to look for the love, beauty and kindness around you.

    ____ If you understand your offender, you may realize that he or she was acting out of unawareness, fear, and even love. You may want to write a letter to yourself from your offender's point of view.

    Don't forget to forgive yourself. ____ But it can rob you of your self-confidence if you don't do it.

A. Why should you forgive?

B. How should you start to forgive?

C. Recognize the benefits of forgiveness.

D. Try to see things from your offender's angle.

E. For some people, forgiving themselves is the biggest challenge.

F. To make your anger die away, try a simple stress-management technique.

G. If you wait for people to apologize, you could be waiting an awfully long time.

同类题4

学习了种子萌芽的条件后,小明突然想到一个问题:吃西瓜时为什么没看到过有萌发的种子,而扔在地上的西瓜种子却会很快萌发呢?于是小明与学习小组的同学一起进行了分析,大家首先根据书本知识,提出了以下假设:

假设一:种子在西瓜内缺乏萌发所需的温度;

假设二:种子在西瓜内缺乏萌发所需的水分;

假设三:种子在西瓜内缺乏萌发所需的空气;

经过理性的思考和讨论,大家认为上述假设中有两个难以成立,你认为假设____ 不成立(写出一个即可),理由是____ .

通过查阅相关资料,他们了解到许多植物的种子成熟后都有休眠的现象,即种子在适宜的条件下仍不能萌发,这是植物重要的适应特征之一.而导致种子休眠的原因很多,西瓜内种子不能萌发是由于果实中存在抑制物质.

为了验证上诉资料是否可信,他们决定对此展开研究,请你与他们一起完成探究过程:

①将一个成熟的西瓜切开,取出里面的种子并洗净,将瓜瓤捣碎后过滤,西瓜汁备用.

②取两个培养皿,分别贴上注有A、B的标签,每个培养皿中均放入多层滤纸,滤纸上各放10颗西瓜种子.

③在培养皿A中的滤纸滴加一定量的清水,在培养皿B中的滤纸上滴加____ .

④将两个培养皿放在温度适宜的环境中,每天添加水或西瓜汁,以保持滤纸湿润,连续观察多天,结果如下:西瓜种子萌发数量记录表

 培养皿

 第1天

 第2天

第3天

 第4天

第5天 

第6天 

第7天 

 A

0

 0

1

 5

7

 9

 9

 B

0

 0

0

0

0

 0

 0

通过上述实验,你认为他们找到的资料是否可信?____ .