题干

人体内磷脂的重要生理作用是(    )

A:细胞内各种膜结构的骨架物质 

B:协助脂溶性物质的吸收

C:氧化分解提供能量 

D:合成脂类激素和维生素D的原料

上一题 下一题 0.0难度 选择题 更新时间:2018-04-07 03:03:50

答案(点此获取答案解析)

A

同类题2

Good morning, class!
    We know that there are too many net bars around us. The Internet is popular and it makes our lives colorful. Many of us like going online very much because we can learn how to use the computer and get more information from the Internet. We can learn English. We can read some good newspapers and magazines. It can make us clever in playing computer games. We can send E-mails to our friends quickly. We can chat(聊天) freely online with our friends. It can help us get in touch with people from all over the world.
    But some students spend too much time in playing computer game and some stay in the net bars all day and all night. Teenagers even get to have boyfriends or girlfriends online. They write too many letters to each other. It takes them too much time to chat online so they do worse and worse in their lessons and they don't study well any more. I think we mustn't get online when it is time for us to study. We can do it in summer or winter holidays. We should get online with adults(成人)--our teacher or parents.
    At the same time, if we have lots of free time, we can do some out-of-class activities at school. We usually have activities from 4:50 to 5:50 in the afternoon. We have different kinds of activities. If you are interested in sports, you can play basketball or football. We can go to the English Corner. We can practice talking in English there. We hope we can spend more time on our subjects or on such activities that we can learn a lot from and less time on the Internet.
    Thank you for listening to me. That's all.