I. Lexics to the text:
1. to consider – ñ÷èòàòü, ðàññìàòðèâàòü
2. to hesitate – êîëåáàòüñÿ, ñîìíåâàòüñÿ
3. the making of starch – îáðàçîâàíèå êðàõìàëà
4. build them into starch and sugar – ïðåîáðàçîâûâàòü èõ â êðàõìàë è ñàõàð
5. ivy – ïëþù
6. vine – like plant – ïîëçó÷åå ðàñòåíèå
7. try an experiment – ïðîäåëàòü ýêñïåðèìåíò
8. to fill a tube – íàïîëíèòü ïðîáèðêó
9. using your thumb – ïðè ïîìîùè áîëüøîãî ïàëüöà
10. upside down – ââåðõ äíîì
11. a bowl of water – ÷àøà ñ âîäîé
12. the mouth of the tube – îòâåðñòèå ïðîáêè
13. to take the thumb away – óáðàòü ïàëåö
14. to push smth. inside the tube – ïîìåñòèòü ÷òî-òî â ïðîáèðêó
15. to set smth. in the sun – ïîñòàâèòü íà ñîëíöå
16. a vacant space – ñâîáîäíîå ïðîñòðàíñòâî
17. oxygen - êèñëîðîä
18. to be produced – îáðàçîâàòüñÿ
II. Read and translate the text:
If you were to ask a chemist what he considered the most important chemical process in the world, he would not hesitate to answer, “The making of starch by plants.”
A green plant is nature’s chemical laboratory. It is able to take carbon dioxide from the air and water from the soil and build them into starch and sugar; the process is made possible by the action of sunlight on the green colouring material of the plant.
Ii you have a growing plant in your home, preferably ivy or some vine-like plant, try this experiment: fill a test tube to the very top with water and using your thumb as a stopper, turn the tube upside down in a bowl of water. Now, being very careful to keep the mouth of the tube under water, take your thumb away and push a branch of the plant up inside the tube, then set the whole arrangement in the sun.
In a few hours you will find what seems to be a vacant space at the top of the tube. This space is really filled with oxygen which was produced by sunlight acting on the leaves of the plant.
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III. Answer the questions on the text:
1. The making of starch by plants is the most important chemical process in the world, isn’t it?
2. What does a green plant take from the air and from the soil?
3. How does a green plant build carbon dioxide and water info starch and sugar?
4. Prove it experimentally. (Describe the experiment).