分别将未分化细胞群培养在植物激素X和植物激素Y浓度比不同的培养基中,未分化细胞群的变

题型:单项选择题

问题:

分别将未分化细胞群培养在植物激素X和植物激素Y浓度比不同的培养基中,未分化细胞群的变化情况如图所示。据图分析下列叙述正确的是()

A.植物激素X是生长素

B.植物激素Y可诱导芽的生成

C.实验所用的未分化细胞群可来自于不同种植物

D.激素X和Y浓度比为1时细胞不能分化

考点:高中生物植物激素调节植物激素调节题库
题型:单项选择题
下列求导运算正确的是(  )
A.(x+
1
x
)′=1+
1
x2
B.(log2x)′=
1
xln2
C.(cosx)'=sinxD.(3x)'=3xlog3e
题型:单项选择题
完形填空(共20小题;每小题1.5分,满分30分)
阅读下面短文,从短文后各题所给的四个选项(A、B、C和D)中,选出可以填入空白处的最佳选项,并在答题卡上将该项涂黑。
When I met Mr Jim Lemon I was a seventeen-year-old freshman at Houston's Jackson Junior High.The chances of my finishing high school were  36  . I was a troubled teenage.
Mr Lemon taught American history and was quite  37  from the other teachers I had known. Not only was he  38  , but also he was a great teacher. He pushed and never tolerated the mediocrity(平庸) that had become my standard.
On the occasion of our first semester report cards, Mr Lemon  39  me aside and asked how it was possible that I was a B student in his class and a C student in the  40  of my classes. I passionately told him about my  41  parents, the local gangs, the drugs, the fights, the police---all of the evils I had been  42  to. It was then that Mr Lemon  43  explained that the only person  44  for my situation was me. And the only person with the  45  to change my situation was me. He  46  me that I was failing not because I was a failure. He inspired me to become a better student and he  47  my life.
Ten years later I was preparing to graduate from a university when I spoke to him again . 48  I did get him on the phone, I told him that I had been saving money so that I could invite him to come to Hawaii at my  49  to be a part of my graduation.
I'll never forget his  50  . He said,"Who is this again?" I was just one of hundreds of the students whose life he changed  51  he had no idea of his influence.
Mr Lemon never came to my graduation, but his  52  taught me another valuable lesson. His final lesson for me was that we will never know or understand the  53  we have on other people's lives. He taught me that we all have the  54  to effect people's lives for the  55  ... Or for the worse.      
小题1:
A.near
B.ready
C.great
D.slim
小题2:
A.kind
B.excellent
C.different
D.same
小题3:
A.strict
B.tough
C.sympathetic
D.warm-hearted
小题4:
A.scolded
B.called
C.pushed
D.dragged
小题5:
A.rest
B.most
C.others
D.all
小题6:
A.qualified
B.learned
C.well-educated
D.divorced
小题7:
A.subjected
B.addicted
C.referred
D.forced
小题8:
A.nervously
B.patiently
C.strictly
D.confidently
小题9:
A.blamed
B.capable
C.struggling
D.responsible
小题10:
A.sense
B.potential
C.direction
D.mood
小题11:
A.persuaded
B.pointed
C.convinced
D.confirmed
小题12:
A.changed
B.turned
C.supported
D.arranged
小题13:
A.While
B.Before
C.When
D.After
小题14:
A.cost
B.expense
C.treat
D.invitation
小题15:
A.attitude
B.unwillingness
C.teaching
D.response
小题16:
A.and
B.however
C.or
D.so
小题17:
A.absence
B.refusal
C.confusion
D.decision
小题18:
A.importance
B.ability
C.impression
D.influence
小题19:
A.duty
B.opportunity
C.responsibility
D.courage
小题20:
A.easier
B.better
C.happier
D.simpler
 
题型:单项选择题

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A.CA中心为每个使用公开密钥的用户发放一个数字证书,数字证书的作用是证明证书中列出的用户合法拥有证书中列出的公开密钥

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坝岸遭受急流冲刷,水流流速(),将根石等料物冲揭剥离。

A.过高

B.较小

C.平缓

D.过缓

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每节车厢有()个客室空调控制盘。

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