TED分享 | 细胞对抗病毒的健康之战（一）：细胞的结构和特性。
You are in line at a grocery store when uh-oh someone sneezes on you. The cold virus is sucked inside your lungs and lands on a cell on your airway lining. Every living thing on earth is made of cells, from the smallest one cell bacteria to the giant blue whale, to you.
你在杂货店排队付账，突然，不妙，有人朝你打了个喷嚏。感冒病毒被吸到了你的肺里，然后降落在你的气道黏膜上。地球上所有的生物都是由细胞组成的，从最小的单细胞到巨大的蓝鲸，还有你都是如此。
词汇讲解1：
be in line 排队
at a grocery store 在杂货店
living thing 生物
be made of 由……组成
Each cell in your body is surrounded by a cell membrane. A thick flexible layer made of fat and proteins that surrounds and protects the inner components. It’s a semi permeable, meaning that lets something pass in and out but blocks others. The cell membrane is covered with tiny projections. They all have functions, like helping cells adhere to their neighbors, or binding to nutrients the cell will need. Animal and plant cells have cell membranes. Only plant cells have a cell wall which is made of richest cellulose that gives the plant structure.
你身体里的每一个细胞都是被细胞膜所包起来的。那是由脂肪和蛋白质组成的一层既厚又有弹性的物质，包围着并保护着细胞内部。细胞具有半渗透性，意味着它让有些东西自由进出，但阻挡其他的东西。细胞膜上有很多突出的部分。比如帮助细胞吸附住邻近的细胞或帮细胞连接上营养物质。动物细胞和植物细胞都有细胞膜，但是只有植物细胞有细胞壁，它由丰富的细胞膜质构成，它赋予了植物支撑结构。
词汇讲解2：
cell membrane 细胞膜
be surrounded by 被……包围
be covered with被……覆盖
membrane 细胞膜
