题干

关于动物代谢的叙述,正确的是(   )

A:动物细胞无氧呼吸的产物是乳酸或酒精

B:动物肌肉细胞不含与无氧呼吸有关的酶

C:动物细胞中糖、脂肪、蛋白质均可被分解提供能量

D:当血糖浓度降低时肝糖元和肌糖元均可分解为血糖

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答案(点此获取答案解析)

C

同类题3

阅读以下材料,说说以下化学探究活动是由哪些环节组成的,将其分别填在相应的括号内.

燃烧是我们经常接触到的一种化学变化.它与我们的生活密切相关.燃烧为人类带来了光明,如果失控也会给人类带来灾难.因此,人类必须了解物质为什么会燃烧,才能控制燃烧,使其更好地造福于人类.

小童想:物质燃烧需要哪些条件?(____ )

(1)可能需要一种可以燃烧的物质;

(2)可能需要一定的温度;

(3)可能需要氧气.(____ )

小童设计了实验方案:

实验1:用镊子分别夹取一小木条和小石子,将它们分别放在酒精灯外焰上加热,观察实验现象.

实验2:用镊子分别夹取一小纸片、小木条、小煤块,分别在酒精灯上点燃,观察实验现象,比较三者点燃的难易程度.

实验3:在桌面上点燃两支蜡烛,在一支蜡烛上方罩上250mL烧杯,观察实验现象.(____ )

小童对实验现象进行了记录和分析:


实验现象

得出的结论

 实验1

小木条燃烧了,小石子不燃烧.

燃烧需要可燃物

 实验2

小纸片最易燃烧,小木条次之,小煤块最难燃烧.

燃烧需要达到可燃物燃烧所需的温度.

 实验3

 桌面上的蜡烛正常燃烧,罩上烧杯的蜡烛燃烧一会儿就熄灭.

 燃烧需要氧气.

小童归纳总结,得出燃烧的条件:可燃物;温度;氧气.(____ )

小童觉得,通过这次探究活动,知道了燃烧的条件,能解释钻木取火、森林灭火等现象和原理,并且体验了像科学家一般探究学习的乐趣.(____ ).

同类题5

阅读下面短文,掌握大意。然后从A.B.C.D四个选项中选出最佳选项 
I was waiting for the bus when I met the woman. “You look   26  . Come and sit here,” she said. “ 27   are you going?”
“I don’t know. I just want to catch a  28    and see what it will be like at the end.”
“I’m afraid you’ll see  29   there. Why don’t you enjoy the sights on the way?”
“How can I do that while my heart’s   30   ?” I asked sadly. My best friend had left me.
The woman seemed to understand my feeling. “Don’t cry, little girl. I’ve had a similar experience to you. Thirty-five   31   ago, my husband left our three children and me. I was deadly sad. I decided to kill myself and the children, so I took    32   to the sea.   33  ,they seemed to know what would happen, so they   34   loudly. Their cry suddenly woke me 35   . How could I  36    my hope to live for one of life’s problems? After that, I worked hard to raise the children. Now they all live   37    and one of them has his own family.
Then the woman gave me a   38  , “We should never wait for the door to   39     before us. We should find the key to the  40   or try to find another way”
The bus came and I got on it with a smile
【小题1】
A.tired
B.excited
C.happy
D.well
【小题2】
A.What
B.How
C.Where
D.When
【小题3】
A.train
B.bus
C.boat
D.plane
【小题4】
A.nothing
B.everything
C.something
D.anything
【小题5】
A.smiling
B.breaking
C.singing
D.dancing
【小题6】
A.days
B.weeks
C.months
D.years
【小题7】
A.her
B.them
C.him
D.it
【小题8】
A.So
B.Or
C.Besides
D.However
【小题9】
A.laughed
B.talked
C.spoke
D.cried
【小题10】
A.in
B.out
C.up
D.down
【小题11】
A.give away
B.give up
C.get up
D.stand up
【小题12】
A.happily
B.sadly
C.badly
D.hopeless
【小题13】
A.cry
B.shout
C.hit
D.smile
【小题14】
A.open
B.close
C.lock
D.mend
【小题15】
A.classroom
B.office
C.door
D.shop