Задание:Use the correct article if necessary. A Friend
Once there was 1. little boy called Bill. He said to his father, "I'm lonely. Where can I find 2. friend?" His dad said, "Behind where we live there is 3. field. It is filled with 4. grass and 5. red pop- pies and 6. corn-flowers. There are 7. big brown and yellow butterflies. Go into 8. field, 9. Bill. Perhaps you will find 10. friend there. 11. little boy went into 12. field. Among 13. poppies he saw 14. tiger. 15. tiger was as yellow as 16. sunshine. Over his coat were 17. beautiful dark stripes. He had 18. very long twitching tail. "Hello, 19. Tiger," said 20. boy "Hello," said 21. beast showing his teeth. "Do you eat 22. little boys?" "No. I only eat 23. sandwiches. I have 24. few wrapped in 25. lunch paper. Would you like some?" They had dinner on 26. grass. Then they played 27. hide-and-seek all over 28. field. They had 29. lot of 30. fun.

1. The (The little boy called Bill)
2. a (where can I find a friend)
3. a (behind where we live there is a field)
4. no article needed (It is filled with grass)
5. no article needed (red poppies)
6. no article needed (cornflowers)
7. no article needed (big brown and yellow butterflies)
8. the (Go into the field)
9. no article needed (Bill)
10. a (you will find a friend there)
11. The (The little boy went into the field)
12. no article needed (field)
13. the (Among the poppies)
14. a (he saw a tiger)
15. The (The tiger)
16. no article needed (sunshine)
17. no article needed (beautiful dark stripes)
18. a (a very long twitching tail)
19. no article needed (Hello, Tiger)
20. the (the boy)
21. the (the beast)
22. no article needed (Do you eat little boys?)
23. no article needed (I only eat sandwiches)
24. a (a few wrapped)
25. no article needed (lunch paper)
26. the (They had dinner)
27. no article needed (hide-and-seek)
28. the (all over the field)
29. a lot of (They had a lot of fun)
30. no article needed (fun)

Explanation:
In this exercise, we need to choose the correct article (the, a, an, or no article) to complete the sentences. Below is the breakdown of the article choices:

1. "A" is used before the noun "little" to introduce the noun phrase "a little boy called Bill" as a new entity.
2. "A" is used before the noun "friend" to indicate that the boy is looking for any friend, not a specific one.
3. "A" is used before the noun "field" because it is being introduced as a new location.
4-7. No article is needed before the nouns "grass," "red poppies," "cornflowers," and "big brown and yellow butterflies" because they are general nouns.
8. "The" is used before the noun "field" because it has already been mentioned before.
9. No article is needed before the proper noun "Bill."
10. "A" is used before the noun "friend" because it is being introduced as a possibility.
11. "The" is used before the noun "little boy" to specify which boy went into the field.
12. No article is needed before the noun "field" because it has already been mentioned before.
13. "The" is used before the noun "poppies" to specify which flowers the boy saw.
14. "A" is used before the noun "tiger" because it is being introduced as a new entity.
15-16. "The" is used before the nouns "tiger" and "sunshine" because they are specific entities.
17. No article is needed before the adjective phrase "beautiful dark stripes."
18. "A" is used before the noun phrase "very long twitching tail" to introduce a new characteristic of the tiger.
19. No article is needed before the proper noun "Tiger."
20. "The" is used before the noun "boy" to specify who is speaking.
21. "The" is used before the noun "beast" to refer to the tiger.
22. No article is needed before the noun phrase "little boys" because it is a general statement.
23. No article is needed before the noun "sandwiches" because it is a general statement.
24. "A" is used before the noun "few" to specify the quantity of sandwiches.
25. No article is needed before the noun phrase "lunch paper" because it is a general statement.
26. "The" is used before the noun "grass" because it is a specific location where they had dinner.
27. No article is needed before the noun "hide-and-seek" because it is a general activity.
28. "The" is used before the noun "field" because it is a specific location where they played.
29. "A lot of" is used before the noun "fun" to indicate a large quantity.
30. No article is needed before the noun "fun" because it is a general statement.

Overall, the choice of article depends on whether the noun is being introduced as a new entity or is a specific entity, and whether it is a general or specific location, among other factors.