下图表示干细胞的三个发育途径。据图回答下列问题: (1)由A细胞形成的B细胞仍然

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问题:

下图表示干细胞的三个发育途径。据图回答下列问题:

(1)由A细胞形成的B细胞仍然保持着其特有的_______能力,A细胞到C细胞的过程是由__________控制的细胞自动结束生命的过程。

(2)若D细胞是胰腺细胞,则结构⑦的主要作用是__________________。

(3)A细胞分化成D细胞的根本原因是_________________。

(4)若D细胞是正在衰老的细胞,则结构⑧发生的变化是_________________。

(5)D细胞吸水膨胀时,⑨的厚度变小,说明⑨具有______________。用丙酮从D细胞中提取脂质,在空气—水界面上铺展成单分子层,测得的单分子层面积是否大于D细胞表面积的2倍?_________________,理由是__________________。

(6)水分子的跨膜运输不同于真正的自由扩散,它最可能与膜上的____成分有关。美国科学家阿格雷试图从人的肾小管管壁细胞膜上寻找这种物质。他以这种细胞为实验材料的依据是_______________。

考点:细胞的分化各种细胞器的结构和功能物质跨膜运输的方式生物膜的流动镶嵌模型细胞凋亡与细胞坏死
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数据库系统其内部分为三级模式,即概念模式、内模式和外模式。其中,______是用户的数据视图,也就是用户所见到的数据模式。

题型:读图填空题

请阅读下列应用文和相关信息,并按照要求匹配信息。

以下是各个电视节目的简介:

A. Wild World-this exciting show takes you around the world to places of unimaginable natural beauty and

     danger. Learn more about our world and see animals as they live in nature.

     Time: Friday 8.30-9.30 pm

B. Sports Sunday-learn what's happening in the world of sport. See how your team performed, find out who

     is playing and watch interviews with all your favourite sports stars.

     Time: Sunday 1-5 pm

C. The Music Man-John Rogers is a musician by day but a secret superhero crime fighter by night in this

     long-running television action drama.

     Time: Weekdays 3.00-4.00 pm

D. Lateline-All the latest news and opinions from around the world. If you want to know where there is

     trouble in the world or the reasons behind the global economic crisis,join our team of award winning

     journalists.

     Time: Weekdays 9-10 pm

E. Entertainment This Week-Covers the world of entertainment. Hear this week's number one song, watch

     the newest movie reviews and listen to all the latest gossip about the stars.

     Time: Saturday 6 pm

F. Pop Star-Hundreds of young and (sometimes) talented performers sing the latest songs and compete to

     see who will become the nation's newest Pop Star.

     Time: Thursday 7.30 pm

以下是每个人的情况介绍,请匹配每个人与其拟选择的电视节目:

( )1. Sarah O'connor. Sarah is trying to decide where she will spend her summer vacation. She has a

            number of different places in mind but is worried about terrorism and her safety so she doesn't

            want to go anywhere that is dangerous or may become dangerous soon.

( )2. John Smith. John loves football and as a senior company manager needs to know the latest economic

            news. He seldom gets home before 10 o'clock at night during the week so he likes to relax in front

            of TV on the weekend.

( )3. Robert Wise. Robert is a fan of action. He loves to watch exciting TV shows whether they are fictional

           or real. He usually only has time to watch TV on weekday evenings as he works during the day and on

           weekends he likes to go hiking and camping.

( )4. Joan Johnson. Joan is a housewife who sometimes feels bored at home so she enjoys watching exciting

            TV shows. When the kids are home on the weekends and after school she never gets a chance to

            watch TV as they want to watch the shows they like.

( )5. Bill West. Bill is a music fan and a musician. He is always trying to hear the newest and most popular

           songs and learn more about his competitors. He is usually free after he finishes work at 5 pm except

           on weekends when he plays with his musical group in a local club.

题型:读图填空题

帧中继工作在OSI模型的()层。。

A.物理层

B.数据链路层

C.网络层

D.A和B

题型:读图填空题

吊篮悬吊平台四周应设置防护栏杆两道,靠近建筑物一侧的栏杆高度不低于()m。

A、0.6

B、0.8

C、1

D、1.2

题型:读图填空题

使用手摇式接地电阻测试仪时,若发现仪表检流计指针有抖动现象,可以(),以消除抖动现象。

A、摇动检测仪

B、打开电池盖

C、变化摇柄转速

D、在控棒周围注水

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