练习册

  • 练习册
  • 试题
    回答.答复 【查看更多】

     

    题目列表(包括答案和解析)

    （6分）据图回答下列问题：

    （1）据图1，若某植物幼苗已表现出向光性，且测得其向光面的生长素浓度为m，则背光面生长素浓度范围是             。
    （2）据图1可知，除草剂灭草的原理是使杂草的生长素浓度大于       （填图1中字母）。
    （3）在探究生长素促进插条生根的最适浓度时，一名技术人员用几种不同浓度生长素溶液处理插条基部，然后在沙床中培养，观察生根情况。图2为生长素促进枝条生根的情况。请结合图1判断，在下列各项浓度值中，最好选用（   ）
    A．3mg·mL-1B．6 mg·mL-1C．9 mg·mL-1D．4.5 mg·mL-1
    （4）生长素的主要作用是促进细胞纵向伸长，其作用机理如图3所示，请回答下列问题：

    ①生长素作用的第一步是与细胞膜上的受体结合，形成“激素—受体复合物”，这一过程体现了细胞膜的              功能。
    ②实验发现，细胞在持续生长过程中，细胞壁将发生一定变化，出现这种现象的原因是由于              （填细胞器）为细胞壁添加了新的成分。
    ③此外，Ca2+ 还能激活细胞中的转录因子，它进入细胞核后，能引起         酶催化mRNA的合成。

    查看答案和解析>>

    假如你是李林，家住北京。你的英国笔友Helen给你发来一封E-mail。请你根据该E-mail的内容给予回复。 要求: 1. 词数80～100。2. 语句完整、通顺、语义连贯，格式正确。  注意: 请将该题答案写在答题纸的指定位置。邮件的开头部分需仿照Helen的E-mail填写完整，不计入要求词数。From: Helen 1987@hotmail.comTo:li-lin87@yahoo.comSubject: Hi, Lin!Dear Li Lin, How have you been recently(近来)  How are your parents  I know your mother is a doctor. What is she doing now  I have read a lot about SARS in China, especially in Beijing, and is it true that all the schools are closed  How do you study your lessons then  I've heard that people are afraid to go out. I'm really worried about you. Please write to me as soon as possible. Good luck!　　　　　　　　　　  Yours,　　　　　　　　　　 HelenFrom:_______To:______Subject:______Dear_____,  ______________________________...

    查看答案和解析>>

    阅读下面的文言文，完成小题。
    王丹，字仲回，京兆下部人也。哀、平时，仕州郡。王莽时，连征不至。家累千金，隐居养志，好施周急。每岁农时，辄载酒肴于田间，候勤者而劳之。其堕懒者，耻不致丹，皆兼功自厉。邑聚相率，以致殷富。其轻黠游荡废业为患者，辄晓其父兄，使黜责之。没者则赙(拿钱财帮助别人办理丧事)给，亲自将护。其有遭丧忧者，辄待丹为办，乡邻以为常。行之十余年，其化大洽，风俗以笃。
    丹资性方洁，疾恶强豪。时，河南太守同郡陈遵，关西之大侠也。其友人丧亲，遵为护丧事，赙助甚丰。丹乃怀缣一匹。陈之于主人前，日：“如丹此缣，出自机杼。”遵闻而有惭色。自以知名，欲结交于丹，丹拒而不许。
    会前将军邓禹西征关中。军粮乏，丹率宗族上表二千斛。禹表丹领左冯翊，称疾不视事，免归。后征为太子少傅。
    时大司徒侯霸欲与交友，及丹被征，遣子昱候于道。昱迎拜车下，丹下答之。昱曰：“家公欲与君结交，何为见拜?”丹曰：“君房①有是言，丹未之许也。”
    丹子有同门生丧亲，家在中山，白丹欲往奔慰。结侣将行，丹怒而挞之，令寄缣以祠焉。或问其故，丹曰：“交道之难，未易言也。世称管、鲍，次则王、贡。张、陈凶其终，萧、朱隙其末②，故知全之者鲜矣。”时人服其言。
    客初有荐士于丹者，因选举之，而后所举者陷罪，丹坐以免。客惭惧自绝，而丹终无所言。寻复征为太子太傅，乃呼客谓曰：“子之自绝，何量丹之薄也?”不为设食以罚之，相待如旧。其后逊位，卒于家。 　　　                                   (《后汉书·卷二十七》)
    【注】①君房：候霸的字。②次则王、贡。张、陈凶其终，萧、朱隙其末：王吉、贡禹均为后汉昭宣时人，二人志同道合；张耳、陈余，两人初为刎颈之交．后兵戎相见；萧育、朱博，最初萧育举荐朱博，后有隙，不能相终。
    【小题1】下列句子中划线词的解释，不正确的一项是    (   ）
    A．其堕懒者，耻不致丹，皆兼功自厉自厉：自我发奋
    B．禹表丹领左冯翊，称疾不视事　视事：办公
    C．家公欲与君结交，何为见拜见拜：看到就拜见
    D．而后所举都陷罪，丹坐以免坐：受牵连获罪
    【小题2】下列各组句子中，划线词的意义和用法相同的一组是（   ）
    A．辄载酒肴于田间辇来于秦
    B．遵闻而有惭色彼节者有间，而刀刃者无厚
    C．其化大洽项王谓其骑曰
    D．丹未之许也始臣之解牛之时
    【小题3】以下六句话分别编为四组，全都表现王丹“资性方洁”的一组是    (    )
    ①王莽时，连征不至                 ②没者则赙给，亲自将护 
    ③自以知名，欲结交于丹，丹拒而不许 ④禹表丹领左冯翊，称疾不视事，免归
    ⑤而后所举者陷罪，丹坐以免         ⑥不为设食以罚之，相待如旧
    A．①②⑤B．①③④C．②③⑥D．②⑤⑥
    【小题4】把文言文阅读材料中划横线的句子翻译成现代汉语。（12分）
    （1）其轻黠游荡废业为患者，辄晓其父兄，使黜责之。(4分)
    （2）寻复征为太子太傅，乃呼客谓曰：“子之自绝，何量丹之薄也?” (5分)
    （3）丹怒而挞之，令寄缣以祠焉。 （3分）

    查看答案和解析>>

    阅读下面短文，简要回答所给问题。
                                                  Thumbs Down to Texting 屈指发短信
         Do you have a mobile phone? Do you send text messages to your friends and family?
        Text messaging or "texting" is becoming very popular. But, scientists have discovered that texting can
      give us problems with our hands. Be careful! Too much texting can cause swelling (肿胀) in our
     thumbs.  Our thumbs were not made for pushing small buttons, over and over.  Scientists call this problem
      RSI.  We spoke to a doctor called Harriet Wilson, who treats many sick people with RSI. She says we
     need to see how much time we are spending in typing text messages.  If we are spending more than 10-15
      minutes at once, we could have problems in the future.
         As mobile phones develop, they are getting smaller with buttons closer together. Texting with a smaller
      phone is worse than using a larger phone with bigger buttons.Using a computer keyboard and playing
     video games can cause the same problem.  So more and more people could find themselves with RSL 
     Among them, most are university students and teenagers, as they do not know the risks of spending so
     much time using computer, video games and mobile phones. If we don't do something about this, too
     many young people could grow up in terrible pain.
        Note: RSI abbr .肢体重复性劳损 (repetitive strain injury).
    1. What is becoming very popular now according to the passage?
        ______________________________.
    2. Does the word "once" mean "one time" in the second passage?
        ______________________________.
    3. What kind of people are easier to have the problem of RSI?
        ______________________________.
    4. What can also cause RSI besides texting?
        ______________________________.
    5. Which is easier to cause the problem of RSI,  using smaller mobile phones or larger ones?
        ______________________________.

    查看答案和解析>>

    根据句意和汉语注释，在答卷标有题号的横线上，写出单词的正确形式。
    【小题1】He seldom __________ (回复) to the e-mails his friends send him.
    【小题2】Our English teacher has offered us some useful __________ (建议). I think they will help us a lot in our English study.
    【小题3】I came here __________ (专门) to invite you to my party.
    【小题4】Listening to music can make you forget your __________ (悲伤).

    查看答案和解析>>


    同步练习册答案