题干

将2个分别装有空气和红棕色二氧化氮气体(ρ二氧化氮>ρ空气)的玻璃瓶口对口对接,中间用玻璃板隔开.抽开隔板后,通过观察瓶内颜色变化推断气体分子是否作无规则运动.对于玻璃瓶的三种放置方法(如图所示),四位同学判断正确的是(  )

A:小华认为甲图放置最不合理

B:小夏认为乙图放置最不合理

C:小梦认为丙图放置最不合理

D:小满认为三种放置方法都不合理

上一题 下一题 0.0难度 选择题 更新时间:2014-04-19 09:56:15

答案(点此获取答案解析)

B

同类题4

阅读下列短文,从每题所给的选项中选出最佳答案。

    During my elementary (基础的) school years, I used to compare my mom with my best friend Tiffany's mom.

    Tiffany's mom always gave her lots of money to buy the most fashionable clothes and favorite food. Her mom allowed her to do anything she liked. I really admired Tiffany. My mom didn't give me much pocket money and she always told me that I should behave myself. I was angry with her.

    Whenever I didn't get what I wanted, I would complain to my mom, Tiffany's mom would give her that! I wish she were my mom. Every time, my mom would calmly say "Poor Tiffany". I couldn't understand her. "She shouldn't be feeling sorry for Tiffany!" I thought. "She should be feeling sorry for me."

    One day, I couldn't help saying to Mom, "Poor Tiffany? Lucky Tiffany! She gets everything she wants! Why do you feel sorry for her?" Iburst into tears.

    My mom sat down next to me and said softly. "Yes, I do feel sorry for her. I have been teaching you a lesson that she will never be taught."

    I looked up at her. "What are you talking about?" Mom said with care, "One day she will really want something. Maybe she'll find out that she can't have it. Her mother won't always be around to give her money, and what's more, money can't buy everything."

She continued, "I have taught you useful lessons by not giving you everything you want. You'll know how to be yourself and save money, but she won't. You'll understand that you need to work hard to get the things that you want but she won't. When Tiffany is a grown woman, she'll wake up one day and she will be wishing that she had a mom like the one you've got. Life lessons are more important than modern clothes and delicious food."

    It took some time, but I finally understood my mom's words. Now I am a happy and successful woman.