Model: —
A general question.
— An answer (+. -).
Ex. 3. Макс up short dialogues according to the model.
Example: — Are you a student?
— Yes, I am. / No, I’m not.
Ex. 4. Give detailed answers to the questions.
1. What do you know about the periodicity in chcmistry? 2. How did
chemistry change with time? 3. What were the most important discoveries
of the 19th century? 4. What can you say about the 20th-century chcmistry?
Ex. 5. Discuss the following topics:
1. The Achievements of the Ancicnt Civilizations.
2. The Principal Discoveries in the History of Chemistry and their
Importance.
3. The Twenty-First-Century Chemistry.
4. New Frontiers in Chemistry.
WHAT IS IT?
A substancc which cannot be divided into a simpler one by ordinary
chcmical methods.
Достарыңызбен бөлісу: