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为了探究甲状腺激素对蝌蚪发育的影响，某生活兴趣小组同学设计了如下的实验步骤： ①取两个相同的玻璃缸，分别贴上标签A、B． ②在A缸和B缸中分别加入2000ml河水，并各培养10只同种、同一批的小蝌蚪． ③A缸隔天加甲状激素5mg，持续5次．B缸不加甲状腺激素，其他培养条件相同． ④每两天换1000ml河水，每天喂几粒饭或少许熟蛋黄粉和少许切碎的菜叶． 实验结果如下表： 实验要素 后肢长出的平均时间（天） 前肢长出的平均时间（天） 尾脱落的平均时间（天） 尾脱落时的平均体长（cm） A缸 4 7 26 0.7 B缸 5 9 37 1.3 根据实验步骤和结果，回答下列问题： （1）实验中A缸和B缸的规格、水量、蝌蚪的数量、大小等条件都必须保持一致目的是______；其中A缸作______组，B缸作______组． （2）根据实验结果你能得出的结论是______． （3）甲状腺激素是由______分泌的．
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B.
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8，8
D.
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【单选题】对脉搏生理性变化的叙述错误的是
A.
幼儿比成人快
B.
同龄男性比女性快
C.
老年人比较慢
D.
情绪激动时快
E.
休息睡眠时减慢
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【单选题】The second paragraph attempts to tell us that ______.
A.
mental abilities are characteristic of humans only
B.
we are still not certain about the difference between thought and thinking
C.
all animal species are in fact capable of thought
D.
we need to research further to get an appropriate definition of the term 'thought'
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【单选题】TMS 320C 54X DSP采用改进的哈佛结构,围绕( )条16位总线建立。
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B.
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【单选题】Human societies have experienced so many wars, but have you ever thought about what a war really is? War may be a natural expression of biological instincts and drives toward aggression in the human s...
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【单选题】TMS320C54X DSP 采用改进的哈佛结构,围绕( B )条16 位总线建立
A.
4
B.
8
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【单选题】Although origin in ritual has long been the most popular, it is by no means the only theory about how the theater came into being. Storytelling has been proposed as one alternative. Under this theory,...
A.
The presence of theater in almost all societies is thought to have occurred because early story tellers traveled to different groups to tell their stores.
B.
Many theorists believe that theater arises when societies act out myths to preserve social well-being.
C.
The more sophisticated societies became, the better they could influence desirable occurrences through ritualized theater.
D.
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【单选题】对脉搏生理性变化的叙述错误的是
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幼儿比成人快
B.
同龄男性比女性快
C.
老年人比较慢
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E.
休息睡眠时减慢
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【单选题】What is the legal affairs reporter's opinion on this issue?
A.
Copyright law doesn't apply to non-humans.
B.
She is not sure what the founding fathers of copyright law thought.
C.
We all love animals and they should be treated equally as humans.
D.
The issue between animal rights and human rights will never stop.
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相关题目：
【单选题】TMS320C54X DSP采用改进的哈佛结构,围绕__条__位总线建立。
A.
16，8
B.
8，16
C.
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D.
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【单选题】对脉搏生理性变化的叙述错误的是
A.
幼儿比成人快
B.
同龄男性比女性快
C.
老年人比较慢
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【单选题】对脉搏生理性变化的叙述错误的是
A.
幼儿比成人快
B.
同龄男性比女性快
C.
老年人比较慢
D.
情绪激动时快
E.
休息睡眠时减慢
查看完整题目与答案
【单选题】The second paragraph attempts to tell us that ______.
A.
mental abilities are characteristic of humans only
B.
we are still not certain about the difference between thought and thinking
C.
all animal species are in fact capable of thought
D.
we need to research further to get an appropriate definition of the term 'thought'
查看完整题目与答案
【单选题】TMS 320C 54X DSP采用改进的哈佛结构,围绕( )条16位总线建立。
A.
4
B.
8
C.
12
D.
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【单选题】Human societies have experienced so many wars, but have you ever thought about what a war really is? War may be a natural expression of biological instincts and drives toward aggression in the human s...
A.
it threatens the existing social systems
B.
it is influenced by society
C.
it has roots in religious conflicts
D.
it is directed against institutions of law
查看完整题目与答案
【单选题】TMS320C54X DSP 采用改进的哈佛结构,围绕( B )条16 位总线建立
A.
4
B.
8
C.
12
D.
16
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【单选题】Although origin in ritual has long been the most popular, it is by no means the only theory about how the theater came into being. Storytelling has been proposed as one alternative. Under this theory,...
A.
The presence of theater in almost all societies is thought to have occurred because early story tellers traveled to different groups to tell their stores.
B.
Many theorists believe that theater arises when societies act out myths to preserve social well-being.
C.
The more sophisticated societies became, the better they could influence desirable occurrences through ritualized theater.
D.
Theater may have come from pleasure humans receive from storytelling and moving rhythmically.
查看完整题目与答案
【单选题】对脉搏生理性变化的叙述错误的是
A.
幼儿比成人快
B.
同龄男性比女性快
C.
老年人比较慢
D.
情绪激动时增快
E.
休息睡眠时减慢
查看完整题目与答案
【单选题】What is the legal affairs reporter's opinion on this issue?
A.
Copyright law doesn't apply to non-humans.
B.
She is not sure what the founding fathers of copyright law thought.
C.
We all love animals and they should be treated equally as humans.
D.
The issue between animal rights and human rights will never stop.
查看完整题目与答案