Вставьте артикли, где они необходимы.
1. I think we must call ... doctor.
2.Do you know ... Browns? They live next to us.
3. ... Peter is tallest in ... class.
4. There are some beautiful towns in ... north of Italy.
5. ... Greece is in ... south.
6. ... President is ... head of state in ... US.
7. What did you have for ... dinner?
8. ... Trafalgar Square is in ... London.
9. ... White House is ... home of ... President of ... US.
10. ... British Museum has some very interesting exhibitions.
11. Take ... pen and make ... exercise in written from.
12. ... Hyde Park is very famous all over ... world.
13. In spring ... sky is blue and ... sun is shining.
14. Do you read ... Daily Telegraph or ... Sun?
15. Did you visit ... Kremlin, too?
16. My son studies at ... Moscow University.
17. Are you going to ... theatre tonight?
18. My brother is in ... hospital, because he need an operation.

Вот варианты, как должны выглядеть предложения с добавлением артиклей, где это необходимо:

1. I think we must call a doctor.
2. Do you know the Browns? They live next to us.
3. Peter is the tallest in the class.
4. There are some beautiful towns in the north of Italy.
5. Greece is in the south.
6. The President is the head of state in the US.
7. What did you have for — dinner? (артикль не нужен)
8. Trafalgar Square is in — London. (артикль не нужен)
9. The White House is the home of the President of the US.
10. The British Museum has some very interesting exhibitions.
11. Take a pen and make an exercise in written form.
12. Hyde Park is very famous all over the world.
13. In spring, the sky is blue and the sun is shining.
14. Do you read the Daily Telegraph or the Sun?
15. Did you visit the Kremlin, too?
16. My son studies at — Moscow University. (артикль не нужен)
17. Are you going to the theatre tonight?
18. My brother is in the hospital, because he needs an operation.

Артикли здесь выполняют свои основные функции: "the" употребляется для уточнения конкретного объекта (например, the Browns — конкретная семья, о которой идет речь), а "a" используется при упоминании объекта впервые или когда он не конкретизируется (например, a doctor).