You carry 1.3 kg fatty material in your head that controls everything you will ever do.This fantastic control center lets you think，learn，create，and feel emotions.It also controls everything your body does.What is this amazing machine？It's your brain — a structure so amazing that the famous scientist James Watson called it "the most complex thing we have yet discovered in our universe".
Imagine your cat jumped onto the kitchen counter，and was about to step onto a hot stove.You would have only few seconds to act.In situations like this，your brain reads the signals from your eyes and quickly calculates when，where and at what speed you need to run to save her.Then it tells your muscles to move.No computer can match your brain's great ability to download，process，and react to the flood of information from your eyes，ears and other sensory organs.
If a bee lands on your foot，sensory neurons （感觉神经元） in your skin send this information to your brain at a speed of more than 240 kilometers per hour.Your brain then uses motor neurons （运动神经元） to send a message back to your foot：Shake the bee off quickly!Motor neurons can send this information at more than 320 kilometers per hour!
Your brain has about 100 billion tiny cells：neurons — it would take you more than 3 ，000 years if you tried to count them all.Whenever you dream，laugh，think，see or move，tiny chemical and electrical signals are racing between these neurons along billions of tiny neuron pathways.Believe it or not，the activity in your brain never stops.Countless messages fly around inside it every second，like a super-fast game of table tennis.Your neurons create and send more messages than all the phones in the entire world.And although a single neuron produces only a tiny amount of electricity，all your neurons together can produce enough electricity to power a light bulb.
（1）What does "the most complex thing" mean？ BB
A．A supercomputer.
B．Human brains.
C．The universe.
D．Our emotions.
（2）What can we know from the passage？ CC
A．Brains can download more information than any computer.
B．The cat plays an important role in testing human brain power.
C．Motor neurons in human brains serve to send messages.
D．Your brains can use neurons to send messages back faster than bees'.
（3）The author mentions "to power a light bulb" in Para.4 to show CC.
A．neurons can create lots of messages
B．how many active tiny cells the brain have
C．how much electricity the brain can produce
D．there is countless information in the brain
（4）What is the main idea of the passage？ AA
A．The powerful brain is a wonderful machine.
B．Brains work well in controlling body movements.
C．The brain is the most complex structure in the universe.
D．Human brains are made up of numerous neurons.
【答案】B；C；C；A
【解答】
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发布：2024/6/27 10:35:59组卷：10引用：2难度：0.5
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1．Rainforests provide much of the world's oxygen.People have been trying to protect them for years.But another type of forest，the cloud forest，is just as important to humans.
These forests are at the tops of mountains，generally near the equator （赤道）.These wet，wooded mountaintops are mainly in African and Central and South American countries.They are called "cloud forests" because their height allows for the formation of clouds among the trees.The trees in these forests pull water out of the clouds.The water gathers on the leaves and falls into small rivers below，which flow into towns at the bottom of the mountain.The yearly rainfall in these areas is about 180 centimetres.Cloud forests can pull in up to 60 percent of that.The water is important to the plants and the people in the area.It helps them survive.
Cloud forests are also home to countless species of plants that can't be found anywhere else.One small cloud forest has as many types of plants as there are in all of Europe.In fact，there are so many that scientists haven't made a complete list of them yet.
These forests are being destroyed at increasing speed.Trees are being cut down，and roads are being built in their place.Some people have a goal to get government money to protect the forests.But they have had little success so far.Another way is to take the place of the destroyed plants with new ones.That，too，has been difficult because the plants are so special.There's plenty of work to be done，but saving the cloud forests is still possible with creative solutions.
（1）Where can you probably find cloud forests？
A．In North America.
B．Far from the equator.
C．In an African country.
D．At the foot of mountains.
（2）How much rainfall is pulled in by the cloud forests in those areas every year？
A．About 60 cm.
B．About 108 cm.
C．About 180 cm.
D．About 300 cm.
（3）What is the main idea of paragraph 3？
A．Europe is short of plant types.
B．Scientists are working on a list.
C．Cloud forests are getting smaller.
D．Cloud forests house many plants.
（4）What will be discussed in the following part of the text？
A．Ways to protect cloud forests.
B．Goals of cloud forest protectors.
C．Difficulties in planting new trees.
D．Successes of getting wide support.
（5）Where can we probably find the text？
A．In a storybook.
B．In a travel guide.
C．In a chemistry textbook.
D．In a geography magazine.发布：2025/1/1 18:0:1组卷：7引用：3难度：0.5 -
2．The baby is just one day old and has not yet left hospital．She is quiet but alert（警觉）．Twenty centimeters from her face researchers have placed a white card with two black spots on it．She stares at it carefully．A researcher removes the card and replaces it by another，this time with the spots differently spaced．As the cards change from one to the other，her gaze（凝视） starts to lose its focus - until a third，with three black spots，is presented．Her gaze returns；she looks at it for twice as long as she did at the previous card．Can she tell that the number two is different from three，just 24 hours after coming into the world？
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（1）The experiment described in Paragraph 1 is related to the baby's．
A．sense of hearing
B．sense of sight
C．sense of touch
D．sense of smell
（2）Babies are sensitive to the change in．
A．the size of cards
B．the colour of pictures
C．the shape of patterns
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（3）Why did the researchers test the babies with drumbeats？
A．To reduce the difficulty of the experiment．
B．To see how babies recognize sounds．
C．To carry their experiment further．
D．To keep the babies' interest．
（4）Where does this text probably come from？
A．Science fiction．
B．Children's literature．
C．An advertisement．
D．A science report．发布：2025/1/1 17:0:1组卷：3引用：4难度：0.5 -
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B．Record.
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（3）What is the main idea of Paragraph 4？
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（4）In the last paragraph，Jim states that.
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D．he likes to go to places that few people bother to visit发布：2025/1/1 18:0:1组卷：20引用：3难度：0.7
