Although most teenagers hate reading 1. /an/the/-] books, I spend hour a day on an interesting book.

Решение:

Пропущено слово 'a' или 'an' перед 'hour', и 'some' или 'an' перед 'books'.

1. Although most teenagers hate reading 1. some /an/the/-] books, I spend
2. hour a day on an interesting book.

Ответ: some