综合填空，根据首字母和汉语意思完成下列短文，注意用正确的形式填空。
Everyone has two eyes . Of course our eyes aren’t lonely. When you feel sad or you fail to meet ___ (某人), tears will come down from your eyes as ____ (像往常一样). When you are happy, ______（特别） when you laugh hard, tears will come down from your eyes,__ _ . But tears have a more important job than showing your f_____ .
Tears keep your eyes clean and healthy. They wash away dirt and germs(细菌) just like bath. Your eyes also need tears to keep them w___. And eyes must be wet so that they can move smoothly. Your eyes are busy looking here and there all day long. They move quickly from one thing to another. If you didn’t have tears, your eyes will have t_____ seeing something clearly, and soon you would be blind.
Tears is _____(有益的).Maybe you don’t like tears, but your eyes can’t do without them. As we know , foggy weather will do harm to our eyes, so we must protect our ________ (环境) from being polluted.
We are p___ of our eyes.