问题 选择题

如图,有关零排放车载燃料电池叙述正确的是(    )

A.正极通入H2,发生还原反应

B.负极通入H2,发生还原反应

C.导电离子为质子,且在电池内部由正极定向移向负极

D.总反应式为2H2+O2 = 2H2O

答案

答案:D

题目分析:在燃料电池中,通入燃料H2的电极为负极。负极发生氧化反应。通入空气或氧气的电极为正极,正极发生还原反应。在电解质溶液中,根据同种电荷相互排斥,异种电荷相互吸引的原则,由于是酸性介质,所以导电离子质子向负电荷较多的正极移动。该燃料电池的总反应式为2H2+O2 = 2H2O。因此正确选项为D。

填空题
阅读理解

阅读理解。

     This is the place for you to come to share stories with other real kids who are trying hard to improve their

bodies and minds! Did you score a goal in your soccer game? Have you got rid of a bad habit? Are you working

to reduce your stress in life? Tell the world what makes your body and mind healthy!

     Posted by Dp, Ohio

     I have been working on a fitness equipment to exercise for over four months. I have completed my goal of

losing weight and I am very proud of myself. That is so cool!

     Posted by MK, Missouri

     I was always tired at school, because I used to stay up late watching TV. I even fell asleep one day in my

history class, and when I woke up, the teacher was looking at me and laughing! I decided that minute to start

going to bed on time. It's kind of a drag missing the shows I like, but I can tell my body loves it-I feel so much

better!

     Posted by SP, Georgia

     Last year, I didn't make the soccer team at school. I didn't want to try out again this year, but a few weeks before tryouts (选拔赛), I started kicking the ball around and practicing. When tryout day came, I decided to give it another shot. Guess what? I made the team!

     Posted by JS, New York

     I'm deaf, so I've had more trouble playing sports than other people. But who wants to sit at home all the

time? I like to play basketball with guys in my neighborhood. I can't hear the ball bounce (弹起) or listen to the

guys call players, but I've taught them to use some sign language, and so far, we've been unstoppable!

1. The kids mentioned in the text came here _____.

A. to make new friends

B. to learn to tell stories

C. to talk about their efforts to keep fit

D. to share weight-losing experiences

2. The achievement that SP, Georgia has made is that _____.

A. he was admitted to the school soccer team

B. he scored a goal in an important soccer match

C. his soccer skills have improved a lot this year

D. he helped the school soccer team win an important match

3. Who taught other kids sign language?

A. DP, Ohio

B. JS, New York

C. SP, Georgia

D. MK, Missouri

4. The underlined part "a drag" in the text probably refers to something that is _____.

A. satisfying

B. rewarding

C. puzzling

D. annoying