Решение:
Вставляем артикли a/an перед исчисляемыми существительными в единственном числе, когда говорим о чём-то впервые или в общем смысле. Артикль the используем, когда говорим о конкретном предмете или когда он уже упоминался.
- I'll come back in a minute.
- I was in North America, but I have never been to South America, South Africa for a long time?
- Did your uncle live in the United States?
- A kangaroo doesn't live in South America, does it?
- Are there many industrial cities in Central America?
- What was the weather like in the South Pole?
- What animals live in the North Pole?
- The North-Eastern part of the United States is called New England.
- Boston is one of the oldest cities in the United States.
- The Popovs want to go to South at the end of August.
Ответ: a, North, South, South, a, the, United, A, South, Central, the, the, the, the, The, United, New, Boston, the, the, The, South, the, August.