A
Exercising regularly not only helps you keep slim, but also improves your overall health and well-being. Different exercises produce different results, as they focus on alternate parts of the body. There are four broad exercise categories: endurance, strength, flexibility, and balance. Many people often only focus on one exercise type, but including all four in your workout will produce better results and reduce your risk of injury.
Endurance
Endurance exercises increase your breathing and heart rate. By doing endurance exercises, you are working to keep your heart, lungs, and blood-flow system healthy while improving your total fitness. Over time these activities will make everyday activities seem easier.
Strength
If you want to build up your muscles, then strength exercises, which are also known as "resistance training", are right for you. Even the slightest increase in strength can make a huge difference in your ability to carry out daily tasks. Developing strong muscles also reduces your risk of weak bones.
Flexibility
Flexibility exercises help stretch your body's muscles. This allows for more freedom of movement for other exercises and can also improve your range of motion, posture, ability to breathe deeply, and blood flow. Also, it reduces the muscle tension caused by stress.
Balance
Balance exercises help prevent falls and are especially important to older adults, helping them stay independent. Most good balance exercises are ones that keep you constantly moving with your feet on the ground. Heel — to — toe walking and standing on one foot are simple ways to improve balance.
21. What does the writer advise people to benefit from the exercise rules?
A. By concentrating on one training aspect at a time.
B. By combining all the four exercise types together.
C. By having sufficient rest to reduce the risk of injury.
D. By timing the speed and lengthening the training time frequently.
22. Which exercise types are efficient to better a person's blood-flow system?
A. Strength and Balance B. Flexibility and Balance
C. Endurance and Flexibility D. Endurance and Strength
23. Which part of the body benefit more from strength and flexibility?
A. Arms. B. Legs. C. Bones D. Muscles
【答案】21. B 22. C 23. D
【解析】
【分析】本文是一篇说明文。文章主要介绍运动分为四大类：耐力、力量、柔韧性和平衡，在运动的时候包括这四种运动类型将产生更好的结果，并减少受伤的风险，并分别介绍了这四种类型的好处和怎样减少风险。
【21题详解】
细节理解题。根据第一段 “Many people often only focus on one exercise type, but including all four in your workout will produce better results and reduce your risk of injury. ”（ 很多人通常只关注一种运动类型，但在你的运动中包括这四种运动类型将产生更好的结果，并减少受伤的风险。）可知作者建议运动的时候包含这四个运动类型，将产生更好的结果。故选B。
【22题详解】
细节理解题。根据Endurance中
“By doing endurance exercises, you are working to keep your heart, lungs, and blood-flow system healthy while improving your total fitness.”（ 通过耐力练习，你可以保持你的心、肺和血液循环系统的健康，同时提高你的整体健康水平。）和Flexibility中的“This allows for more freedom of movement for other exercises and can also improve your range of motion, posture, ability to breathe deeply, and blood flow. Also, it reduces the muscle tension caused by stress.” （这样可以让你有更多的自由来做其他的运动，也可以改善你的活动范围，姿势，深呼吸的能力和血液流动。）由此可知Endurance和Flexibility可以有效的改善人体的血液循环，故选C。
【23题详解】
细节理解题。根据Flexibility 中的“Also, it reduces the muscle tension caused by stress. ”（ 此外，它还能减少因压力引起的肌肉紧张。）和Strength中的“If you want to build up your muscles, then strength exercises, which are also known as ‘resistance training’, are right for you.（如果你想增强你的肌肉，那么力量练习，也被称为“阻力训练”，适合你。）由此可知，
Strength 和Flexibility 两项锻炼都是对muscles 有益。故选D。
【点睛】一般定位关键词适用于解答细节理解题。通过定位关键词解题，考生在阅读题干时，把题干中有标记意义的词或词组标记出来，或者选项中的关键词，然后用这个词回到原文当中定位。如小题2题干中的blood-flow system，再如小题3题干中的strength and flexibility，可以帮助快速找出答案。
