Przeczytaj tekst, z którego usunięto pięć zdań. Wpisz w ;uki (1-5) litery, którymi oznaczono brakujace zdania ( A-G), tak aby powstał logiczny i spójny tekst. Uwaga: dwa zdania zostały podane dodatkowo i nie pasują d żadnej luki.

Humprey Dave may not be the most famous scientist and inventor in history but his work was very important. As a chemist, be discovered several elements including potassium,sodium and calcium.
However. important as these discoveries were he is remembered more for his Davy Lamp. Before 1815, miners took candles underground with them when they were working. 1......................... There were no batteries or light bulbs at that time but Davy found a way to improve safety. It was a simple idea. 2................. This was similar to what people now put on windows in the summer to allow air in but keep flies out. With Davy's lamp, air could get in to keep the flame lit but the flame couldn't escape and cause an explosion. That was impressive enough but the lamp did more. If there were dangerous gases in the air, the flame burned higher.3.............In addition, miners could test the air for poisonous gases. Air normally contains about 22% oxygen. When oxygen levels dropped below 17% the lamps went out.Miners could still breathe at that level of oxygen and might not realise that anything ws wrong. The lamp gave them an early warning of danger and allowed them to escape before they were overcome by carbon dioxide.Unfortunately, greed prevent the lamps from saving as many lives as they could. 4...................... It was now possible to spend less on fans as there were fewer explosions. This meant that the air the miners were breathing was actually less healthy than it had been before. The lamps were also easily damaged which menat that, with the poor ventilation, explosions were almost as frequent as they had been. Another problem was that the lamps were't as bright as bare candles. 5................ Despise its faults, the Davy Lamps, along with other similar lamps which appeared at the same time, did help to reduce mining accidents although they stayed at very high levels until electric lamps started to appear in the late nineteenth century.



A. They allowed mine owners to cut costs.
B. It also had a blues colours
C.Test showed that the lamps were safe
D.These often caused explosions because of dangerous gases in the mines
E.Some people argued against their introduction because of this.
F.This made working more difficult.
G.He put the candle into a lamp and fitted a net around it