有的同学爱吐口水,以为口水跟痰一样,是脏东西,其实不然。“口水”的科学名字叫唾(tuò)液。我们口腔里有许多唾液腺(xiàn),会分泌出唾液来。唾液是消化器官的“卫士”,本领大着呢。我们吃东西时,它润湿食物,利于吞咽;交谈时,它又滋润口腔,不轻易就“口干舌燥”;口中有了食物 Some students spit saliva, that saliva with the same sputum, is a dirty thing, it is not. The scientific name for saliva is tuò liquid. There are many salivary glands in our mouth that will secrete saliva. Saliva is the “guardian” of the digestive organs, with a great deal of skill. When we eat, it moistens the food, which is good for swallowing. When talking, it moistens the mouth and does not easily “thirsty.” There is food in the mouth