15.Improving masks throughout (自始至终) time Masks, a simple protective tool, have been used by people for a long time. They can protect us from other harmful things, such as smog (雾霾) and chemicals (化学物品). (1)
was the protective mask first invented and how did it develop? Let's take a look.
1st century
At this time, lots (2)
people in the Roman Empire worked underground. Many died of lung (肺部) diseases caused by dust. Pliny the Elder (23—79), a Roman philosopher (哲学家), used animal bladders (膀胱) to protect miners (矿工) from the dust. This (3)
(be) the first recorded use of protective masks.
16th century
Italian artist and inventor Leonardo da Vinci (1452—1519) advised people to wear a cloth dipped (蘸) in water over their (4)
(face) to protect against harmful chemicals.
(5)
(十九) century
In 1848, American Lewis Hassley became the first person to patent (注册专利) a protective mask. In 1897, Polish-Austrian doctor Johann von Mikulicz Radecki designed a simple mask (6)
one layer (层) of gauze (纱布). He advised medical workers to wear it, too. This was the first use of a surgical (外科的) mask.
20th century
In 1910, the pneumonic plague (肺鼠疫) broke out in Northeast China. Chinese doctor Wu Liande designed (设计) a face mask called "Wu's mask". It was made with two layers of gauze. The mask (7)
(praise) by experts around the world because it could be produced easily (8)
cheaply.
Today
With several outbreaks of flu and the air pollution in recent years, masks have (9)
(继续) to develop. For example, in 2012, when China suffered (遭受) from smog, mask models such as N95 and KN90 became popular. They can filter out (过滤掉) fine particulate matter (微粒物). China is now the world's (10)
(large) mask producer, making about half of the world's masks.