【托福真题_英语外教一对一培训】栏目更新了TOEFL托福阅读真题及答案（77），以下为具体内容：

　　TOEFL托福阅读真题文章：

　　The relationship between certain plant species and specific soil types has been a subject of great interest for botanists and agricultural scientists. One particularly notable example is the symbiosis observed between mycorrhizal fungi and the roots of forest trees. Mycorrhizae are fungal networks that form a close association with plant roots, extending far beyond the root tip into the soil. These fungal hyphae significantly enhance the plant's ability to absorb water and nutrients, particularly phosphorus, which is often scarce in forest soils.

　　The mechanism behind this beneficial interaction is complex. The fungal hyphae, which can grow much longer and finer than plant roots, effectively increase the surface area available for nutrient and water uptake. In return, the plant provides the fungi with carbohydrates, produced through photosynthesis, which the fungi cannot themselves generate. This mutualistic relationship is crucial for the health and growth of many tree species, especially in nutrient-poor environments.

　　Studies have shown that the presence of mycorrhizal fungi can dramatically improve tree survival rates and growth rates. For instance, young trees in nutrient-depleted soils often show better development when associated with these fungi. Furthermore, mycorrhizal networks can connect different trees, allowing for the transfer of resources, such as carbon and nutrients, between them. This "wood-wide web" hypothesis suggests that mycorrhizal networks play a vital role in the overall ecosystem connectivity and resilience.

　　However, the success of this symbiosis is not universal. Environmental factors like soil pH, temperature, and moisture significantly influence the abundance and activity of mycorrhizal fungi. Additionally, not all plant species form mycorrhizal associations equally; some are considered mycorrhizal generalists, forming associations with a wide range of fungi, while others are specialists. Understanding these dynamics is essential for developing sustainable agricultural practices, such as selecting appropriate plant species for specific soil conditions or using mycorrhizal inoculants to enhance crop yields.

　　TOEFL托福阅读真题题目：

　　1. According to the passage, what is the primary role of mycorrhizal fungi in the symbiosis with plant roots?

　　(A) To protect the plant roots from pathogens.

　　(B) To provide the plant with water and essential nutrients.

　　(C) To help the plant absorb sunlight more efficiently.

　　(D) To store water in the soil for the plant's use.

　　2. The word "symbiosis" in the first paragraph is closest in meaning to:

　　(A) Competition

　　(B) Independence

　　(C) Cooperation

　　(D) Parasitism

　　3. What does the passage suggest about the mechanism of nutrient exchange in the mycorrhizal relationship?

　　(A) The plant produces nutrients that the fungi need.

　　(B) The fungi absorb nutrients from the air and transfer them to the plant.

　　(C) The fungi provide nutrients to the plant, and the plant provides carbohydrates to the fungi.

　　(D) The plant and fungi exchange nutrients without any direct contact.

　　4. The passage mentions "the wood-wide web" hypothesis in the context of:

　　(A) Describing a type of forest fire.

　　(B) Explaining how trees communicate with each other.

　　(C) Highlighting the importance of mycorrhizal networks in forest ecosystems.

　　(D) Proposing a new method for agricultural irrigation.

　　5. According to the passage, what factors can influence the success of mycorrhizal associations?

　　(A) Only the type of plant species.

　　(B) Only the soil nutrient levels.

　　(C) Soil pH, temperature, and moisture.

　　(D) The presence of other mycorrhizal fungi in the soil.

　　TOEFL托福阅读真题答案：

　　1、(B)

　　2、(C)

　　3、(C)

　　4、(C)

　　5、(C)

　　以上就是TOEFL托福阅读真题答案（77），欢迎大家进入说客英语官网的【托福真题_英语外教一对一培训】栏目，了解更多托福真题、托福考试内容等相关资讯。