Questions 31-36
Completed the flow-chart below
Write ONE WORD ONLY for each answer
Natural rubber production
‘tapping’ -tree is cut and a layer of bark is removed
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Cup(e.g. made of a 31 ______ shell)is attached to collect latex
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Latex is transferred to the ‘factory’
↓
Latex is poured into a 32 ______
↓
Formic acid is added to thicken the latex
↓
Rubber is 33.______ by hand,to make it into a thin sheet
↓
Rubber sheet is put through a mangle (N.B. the only 34.______ in the process)
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Rubber sheets are taken to be 35.______ in a special room
↓
Rubber sheets are purchased by 36.______
Questions 37-40
Complete the notes below.
Write NO MORE THAN TWO WORDS for each answer
History of rubber
Earliest use Rubber tree -originally from Brazil
1525-rubber 37.______ were used in Mexico 19th century
European interest in rubber
Key discovery- ‘vulcanisation’ made rubber stronger and 38.______
Increase in demand when rubber 39.______ were invented 20th century
Substitute for natural rubber was first developed in 40.______ during First World War
答案
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