前程百利小编为大家准备了“托福阅读材料:植物细胞的组成”,供各位备考托福的考生们参考使用,来提高自己的托福成绩!在阅读中希望大家能够学到相关背景知识。
The cells of a plant'are organized into three tissue systems: dermal,vascular, and ground tissue. Each tissue system is continuous throughout theplant's body. The specific characteristics of each tissue, however, are different in the different organs ofthe plant.
The dermal tissue system is the "skin" of the plant. The dermal system, or epidermis,is a single layer of cells covering the entire body of the plant. The mailn function of the epidermis is to protect the plant. The epidermis also has specialized characteristics for the particular organs it covers. For example, the epidermis ofleaves and stems has a waxy coating that helps the plant conserve water, and the epidermal cells near the tips of the plant's roots help the plant absorb water and nutrients from the soil.
The second tissue system-the vascular system-is the transportation system for water and nutrients. Vascular tissue also helps to support the plant's structure. The third system- the ground tissue-makes up the bulk of a plant, filling all of the spaces between the dermal and vascular tissue systems. Ground tissue functions in photosynthesis, storage, and support.
以上就是前程百利小编为大家带来的托福阅读材料,平时的阅读练习是托福考试阅读备考的重要一环。希望大家利用好每份材料,尽可能多地从中获取知识。预祝大家托福考试取得好成绩。

