A
Brain Chemicals and Happiness
Dopamine(多巴胺):
When you eat your favourite chocolate or win a game, your brain releases(释放) dopamine. This chemical makes you feel excited and motivated. It’s like a “thumbs-up” signal that encourages you to repeat enjoyable activities. For example, students often feel a dopamine rush when they solve a difficult maths problem!
Endorphins(内啡肽): Natural Painkillers(止痛药)
After running a long race or laughing with friends, your body produces endorphins. These chemicals help reduce pain and create a calm, happy feeling. That’s why people feel relaxed after exercising—endorphins act like nature’s medicine. Even eating spicy(辣的) food can trigger(触发) this helpful chemical!
Serotonin(血清素): The Mood Balancer
Sunlight and friendly conversations make serotonin levels high. This chemical helps you feel peaceful. Low serotonin might make people feel worried or sad. Simple actions like walking in a park or helping others can naturally increase serotonin, keeping your emotional “weather” sunny!
()51. All three sections mainly talk about .
A. how to study chemistry
B. ways to exercise the brain
C. favourite food for students
D. chemicals that affect feelings
()52. Best title for “Dopamine” Section is .
A. Why Maths Problems Are Fun
B. The Chemical That Says “Good Job!”
C. How Chocolate Changes Your Brain
D. A Special Medicine for Students
()53. When do people’s bodies produce endorphins?
A. When watching TV.
B. After eating chocolate.
C. After running.
D. When feeling sleepy.
()54. Why might doctors suggest walking outside to someone feeling sad?
A. To help them make friends.
B. To increase(增加) serotonin naturally.
C. To practise running skills.
D. To learn about weather.
()55. What do dopamine, endorphins, and serotonin have in common?
A. They all come from food.
B. They make people run faster.
C. They help control emotions(情绪).
D. They only work for children.

51. D 【解析】主旨大意题。根据全文可知,本文主要介绍了影响情绪的化学物质以及它们如何影响人的感受。故选D。
52. B 【解析】标题归纳题。根据“When you eat your favourite chocolate or win a game, your brain releases dopamine.”和“students often feel a dopamine rush when they solve a difficult maths problem”可知,强调其作为“鼓励重复愉快活动”的信号,B项作为标题最贴切。故选B。
53. C 【解析】细节理解题。根据“After running a long race or laughing with friends, your body produces endorphins.”可知,跑步后人的身体会产生内啡肽。故选C。
54. B 【解析】细节理解题。根据“Simple actions like walking in a park or helping others can naturally increase serotonin, keeping your emotional 'weather' sunny!”可知,医生建议悲伤的人到户外散步,是为了自然地增加血清素。故选B。
55. C 【解析】推理判断题。根据“This chemical makes you feel excited and motivated.”“These chemicals help reduce pain...”以及“This chemical helps you feel peaceful”可知,多巴胺、内啡肽和血清素有助于控制情绪。故选C。

B
Devon Gallagher, a college graduate from Philadelphia, wants the world to know exactly where she is during her worldwide vacation in a special way.
The traveller, who was born with a congenital bone disease(先天性骨病), lost her right leg at the age of four. Although she had a hard time at first, she now thinks that nothing can stop her from living her best life.
To spread that message, Gallagher shares photos of her travels around the world online, and writes her location across her artificial leg(假肢) before taking a picture. Now she has pictures across Europe, all with the well-known locations written on her artificial leg.
“I get a new leg every two years and I can choose the design(设计) on it. But one day I had a sudden thought to get a chalkboard,” Gallagher said. “My mum and grandmother didn’t like the idea, but my friends liked it and told me to go for it, so I did.”
Gallagher says people often stare when she is writing on her leg. But once she shared the photos, she received only positive feedback(正面反馈). “My leg doesn’t stop me from doing anything I want to do, and I’m able to keep up with my peers(同龄人) and live a pretty great life.”
Gallagher shows us that you should never let anything stand in the way of your dreams. And if you run into difficulties, get creative with it because if life gives you an artificial leg, make art.
()56. Gallagher has only one leg because she .
A. was born with one leg
B. gets hurt at college
C. had a car accident at the age of 4
D. has a congenital bone disease
()57. A(n) is written on Gallagher’s artificial leg each time she takes a picture.
A. disease
B. location
C. message
D. idea
()58. Gallagher shares pictures to .
A. help her friends to spread the message
B. make her mum and grandmother happy
C. tell the world how wonderful her vacation is
D. show that nothing can stop her from living her best life
()59. When people saw Gallagher’s pictures, they .
A. didn’t like her idea
B. gave her positive feedback
C. laughed at her dream
D. helped her choose the design of her leg
()60. The best title of the passage is “”.
A. The Secret to Success
B. Face Difficulty with Smiles and Creativity
C. Wonderful Photos
D. A Vacation to Remember

56. D 【解析】细节理解题。根据“The traveller, who was born with a congenital bone disease, lost her right leg at the age of four.”可知,她只有一条腿是因为有先天性骨病。故选D。
57. B 【解析】细节理解题。根据“and writes her location across her artificial leg before taking a picture”可知,Gallagher拍照前在假肢上写上她的位置。故选B。
58. D 【解析】细节理解题。根据“she now thinks that nothing can stop her from living her best life”“To spread that message, Gallagher shares photos of her travels around the world online”可知,Gallagher在网上分享照片,是为了传递她“不被困难阻碍生活”的态度。故选D。
59. B 【解析】细节理解题。根据“But once she shares the photos, she receives only positive feedback.”可知,当人们看到Gallagher分享的照片后,她都收到了正面的反馈。故选B。
60. B 【解析】标题归纳题。根据全文可知,本文表达了要我们敢于面对困难。B项适合作文章标题。故选B。