在托福考試中，閱讀理解是一個(gè)重要的部分,，了解一些基礎(chǔ)知識(shí)可以幫助考生更好地理解文章內(nèi)容。今天,，我們將探討人類(lèi)頭發(fā)的結(jié)構(gòu)及其功能,。

A human hair is primarily made up of a protein called keratin. It also contains moisture along with trace elements and minerals that are present in the body.

The only living portion of hair resides beneath the scalp. Once hair emerges from the scalp, it becomes non-living tissue.

Hair's natural luster is due to sebum, an oil comprised of waxes and fats. Sebum serves as a natural conditioner and contains antiseptic properties that help combat infections. Excessive sebum can lead to oily hair, while insufficient sebum results in dryness.

On average, hair grows approximately 12 mm each month. If left uncut, it could reach around 108 cm before shedding. Hair tends to grow more quickly during summer and while sleeping. A single strand can last up to seven years.

Healthy hair is remarkably elastic, stretching 20-30% before breaking. In fact, a single strand of hair is stronger than a copper wire of the same thickness. Collectively, the strength of all the hair on a human head can support the weight equivalent to that of 99 individuals.

Different populations exhibit varied hair characteristics. For instance, Scandinavians typically have fine, straight hair, while Central Europeans possess hair that is neither too coarse nor too fine. Individuals from the Indian subcontinent usually have coarser hair, and Middle Eastern people often have strong hair. Chinese and Japanese hair is known for its straightness, whereas Latin American and North African hair can be thick and frizzy.

Notes:

scalp [sk lp] n. the skin covering the top of the head; battle spoils

conditioner: a substance used to improve the texture of hair

antiseptic [, nti'septik] adj. having properties to prevent infection; very clean n. a substance that prevents infection

copper wire: a type of electrical conductor made of copper

Scandinavian [,sk ndi'neivi n; -vj n] n. a person from Scandinavia

coarse texture: a rough or uneven structure

通過(guò)上述內(nèi)容，考生可以在托福閱讀中獲得關(guān)于頭發(fā)的基本知識(shí),，提高對(duì)相關(guān)文本的理解能力,。希望大家在備考中能夠掌握更多的詞匯和句型，以便在考試中取得優(yōu)異成績(jī),！

在準(zhǔn)備托?？荚嚨倪^(guò)程中，閱讀理解是一個(gè)非常重要的部分,。掌握一些背景知識(shí)可以幫助你更好地理解文章內(nèi)容,。在這篇文章中，我們將探討“頭發(fā)功能”的相關(guān)知識(shí)，這不僅能增強(qiáng)你的閱讀理解能力,，還能讓你在托?？荚囍懈佑稳杏杏唷??

1. 頭發(fā)的基本功能

頭發(fā)在人體中扮演著多重角色,。首先,，它能夠提供保護(hù)。頭發(fā)可以防止陽(yáng)光直接照射到頭皮,，減少紫外線的傷害,。此外，頭發(fā)還可以減輕外部環(huán)境對(duì)頭皮的物理傷害,，例如風(fēng)和灰塵,。??

2. 體溫調(diào)節(jié)

頭發(fā)在體溫調(diào)節(jié)方面也發(fā)揮著重要作用。它們能夠形成一層隔熱層,，幫助保持身體的溫暖,。在寒冷的天氣中，頭發(fā)可以減少熱量的流失,，而在炎熱的天氣中,，頭發(fā)則可以幫助散熱。???

3. 社會(huì)和文化意義

除了生理功能外,，頭發(fā)在社會(huì)和文化中也具有重要意義,。在許多文化中，頭發(fā)被視為美的象征,，反映了個(gè)體的身份和社會(huì)地位,。例如，在某些文化中,，長(zhǎng)發(fā)被認(rèn)為是女性的美德,，而短發(fā)則可能代表男性的力量。了解這些文化背景可以幫助你在托福閱讀中更好地理解文章的深層含義,。??

4. 常見(jiàn)托福閱讀題型

托福閱讀部分通常會(huì)涉及以下幾種題型：

• Detail Questions: 這些問(wèn)題要求考生從文章中找到具體的信息,。例如：
  What is one function of hair mentioned in the passage?
• Inference Questions: 這類(lèi)問(wèn)題需要考生根據(jù)文章內(nèi)容進(jìn)行推理,。例如：
  What can be inferred about the cultural significance of hair?
• Main Idea Questions: 這些問(wèn)題關(guān)注文章的主旨,。例如：
  What is the main purpose of the passage?

5. 提高閱讀理解的技巧

為了提高你的閱讀理解能力，以下是一些實(shí)用的建議：

• 廣泛閱讀：多讀不同主題的文章,，尤其是科學(xué)和文化相關(guān)的內(nèi)容,，可以幫助你積累相關(guān)的背景知識(shí)。
• 做筆記：在閱讀時(shí)做簡(jiǎn)要的筆記,，記錄下關(guān)鍵點(diǎn)和生詞,，這有助于加深理解。
• 練習(xí)模擬題：通過(guò)做托福閱讀模擬題，熟悉題型和解題技巧,，可以提高你的應(yīng)試能力,。

6. 預(yù)測(cè)未來(lái)的考試話題

在備考過(guò)程中，了解可能出現(xiàn)的話題是非常重要的,。關(guān)于頭發(fā)的功能可能會(huì)出現(xiàn)在以下場(chǎng)景中：

• Scientific Articles: 涉及生物學(xué)或醫(yī)學(xué)的文章,，討論頭發(fā)的生理功能。
• Cultural Studies: 探討不同文化中頭發(fā)的象征意義,。
• Environmental Topics: 討論氣候變化對(duì)人類(lèi)生活的影響,，包括頭發(fā)在內(nèi)的生理適應(yīng)。

通過(guò)掌握這些知識(shí)和技巧,，你將能夠在托福閱讀中更好地理解與“頭發(fā)功能”相關(guān)的文章,，提高你的考試成績(jī)。祝你備考順利,！??

As a TOEFL test taker, understanding various topics can significantly enhance your reading comprehension skills. One intriguing topic is the biological role of hair. In this article, we will explore the functions of hair, which can help you tackle related reading passages in the exam. ??

1. The Structure of Hair

Hair is primarily made up of a protein called keratin, which is also found in nails and the outer layer of skin. Each hair strand consists of three main parts: the cuticle, the cortex, and the medulla. The cuticle is the outer layer that protects the inner structure, while the cortex provides strength and color. The medulla is the innermost part, which may not be present in all hair types. Understanding this structure is crucial as it relates to the hair's functions. ??

2. Protection from Environmental Factors

One of the primary biological roles of hair is to offer protection. Hair on the scalp shields the head from harmful UV rays and reduces the risk of sunburn. Similarly, eyelashes protect the eyes from dust and debris, while nasal hair helps filter out particles from the air we breathe. This protective function is vital for maintaining overall health. ??

3. Temperature Regulation

Another significant function of hair is its role in regulating body temperature. Hair traps a layer of air close to the skin, providing insulation during cold weather. Conversely, when the body heats up, hair can help facilitate sweating, allowing for cooling. This thermoregulation is essential for maintaining homeostasis within the body. ????

4. Sensory Function

Hair also serves a sensory function. The tiny nerve endings around hair follicles make hair sensitive to touch. This sensitivity allows us to detect even the slightest changes in our environment, such as a gentle breeze or an insect landing on our skin. This sensory feedback is crucial for survival, as it helps us respond to potential threats. ??

5. Social and Cultural Significance

Beyond its biological roles, hair holds substantial social and cultural significance. Different cultures have unique hairstyles that convey identity, status, or beliefs. For example, in some cultures, long hair is seen as a sign of beauty, while in others, certain haircuts signify maturity or belonging to a specific group. Understanding these cultural aspects can enhance your comprehension of reading passages that discuss hair in a broader context. ??

6. Vocabulary to Know

When preparing for the TOEFL, it's essential to familiarize yourself with relevant vocabulary. Here are some terms related to hair biology:

• Keratin - A type of protein that makes up hair.
• Follicle - The structure in the skin from which hair grows.
• Thermoregulation - The process of maintaining body temperature.
• UV Rays - Ultraviolet radiation from the sun that can damage skin and hair.

7. Sample Questions for Practice

To prepare for the TOEFL reading section, consider practicing with these sample questions:

• What are the three main parts of a hair strand?
• How does hair contribute to temperature regulation?
• What cultural significance does hair have in different societies?

8. Conclusion

Understanding the biological role of hair not only enhances your knowledge but also equips you with the skills to tackle related topics in the TOEFL reading section. By familiarizing yourself with the structure, functions, and cultural significance of hair, you can improve your overall comprehension and performance on the test. Good luck with your studies! ??