Face masks have become necessary in our daily life now. But do you really know about them?
The earliest recorded face mask-like objects date back to the 6th century B. C. Some drawings of people wearing a piece of cloth over their mouths were found in Persian tombs（波斯的坟墓）.
In China, face mask-like objects first appeared during the Yuan Dynasty. The king's servants were required to wear masks whenever they served food. It was believed that the masks would prevent the food's smell from being affected by the servants' breath.
In the 14th century, a serious disease called the Black Death spread to Europe. This encouraged the invention of more protective masks. French doctor Charles de Lorme invented the beak（喙）mask, which looked like the head of a bird. It completely covered the wearer's face. The wearer had to see through the glass in the mask. The medicine in the beak section protected the wearer from diseases.
In 1910, a serious disease spread in northwestern China. The Chinese government asked Wu Liande, a medical scientist, to investigate it. Wu discovered that the disease could quickly spread through people's breath. He invented "Wu's mask" and advised people to wear it. With-in four months, the disease was brought under control. Since it was cheap and easy to make, the mask was widely praised and it was the masks we use today.
Over the past few decades（数十年）, some scientists have tried to further improve the face mask. Today, face masks are among the world's best-selling items. They play an important role in our lives.
