. Употребите необходимый артикль.
1. What was first word, which you said? 2. This is fax that I got this morning. 3. Do you often go to centre of city? 4. Here is code to computer. 5. My parents are main people in my life. 6. We live in same street. 7. He took second place in that game. 8. We’ll get off at next stop, which is also last stop. 9. He is man I told you about. 10. What’s name of man who discovered America? 11. concert was great success. 12. You’ll find the index on last page. 13. This is best hotel in town. 14. My flat is on third floor. And my brother’s is on fifth floor. 15. exercise is on next page. Do it for next week. next class will be on Monday.

1. What was the first word that you said?
- The word "first" is used to indicate the order of something, so it requires the definite article "the". Additionally, "word" is a countable noun, so it also requires an article. The correct article to use here is "the" because it refers to a specific word that was said, not just any word.

2. This is the fax that I got this morning.
- The word "fax" starts with a consonant sound, so we use the indefinite article "a" before it. The definite article "the" is used before "morning" because it refers to a specific morning.

3. Do you often go to the center of the city?
- "Center" is a countable noun, but it is being used in a general sense here to refer to any center of the city, so we don't need an article before it. However, "city" is a specific city and requires the definite article "the".

4. Here is the code to the computer.
- "Code" is a countable noun, so it requires an article. In this case, we use the definite article "the" because it refers to a specific code for a specific computer.

5. My parents are the main people in my life.
- "Parents" is a plural countable noun, so it requires an article. Since the sentence is referring to specific parents, the definite article "the" is used. "Main" is used here to specify a specific type of people.

6. We live in the same street.
- "Street" is a countable noun, but it is being used in a general sense to refer to any street. In this case, we don't need an article before it because it is not specific.

7. He took second place in that game.
- "Place" is a countable noun, so it requires an article. Since the sentence is referring to a specific place (second place), the definite article "the" is used.

8. We'll get off at the next stop, which is also the last stop.
- "Stop" is a countable noun, so it requires an article. In this case, "stop" is both the next stop and the last stop, so it requires the definite article "the" to refer to those specific stops.

9. He is the man I told you about.
- "Man" is a countable noun, so it requires an article. Since the sentence is referring to a specific man, the definite article "the" is used.

10. What's the name of the man who discovered America?
- "Name" is a countable noun, so it requires an article. Since the sentence is referring to a specific name and a specific man, the definite article "the" is used for both.

11. The concert was a great success.
- "Concert" is a countable noun, so it requires an article. In this case, the indefinite article "a" is used because it is referring to any concert that was a great success, not a specific one.

12. You'll find the index on the last page.
- "Index" is a countable noun, so it requires an article. The definite article "the" is used because it refers to the specific index of the specific book or document mentioned before. "Page" is also a countable noun, so it requires an article. Since it refers to the specific last page, the definite article "the" is used.

13. This is the best hotel in town.
- "Hotel" is a countable noun, so it requires an article. Since it refers to the specific best hotel in the specific town mentioned before, the definite article "the" is used.

14. My flat is on the third floor. And my brother's is on the fifth floor.
- "Flat" is a countable noun, so it requires an article. The definite article "the" is used as it refers to a specific flat. "Floor" is also a countable noun, so it requires an article. Since it refers to the specific third and fifth floors mentioned, the definite article "the" is used.

15. The exercise is on the next page. Do it for the next week. The next class will be on Monday.
- "Exercise" is a countable noun, so it requires an article. Since it refers to a specific exercise mentioned before, the definite article "the" is used. "Page" is also a countable noun and requires an article. The definite article "the" is used because it refers to the specific next page mentioned. "Week" is a countable noun, but in this case, it is used in a general sense to refer to any week, so we don't need an article before it. "Class" is also a countable noun and requires an article. The definite article "the" is used because it refers to the specific class that will be on Monday.