хотя было очень поздно, он продолжа

хотя было очень поздно, он продолжал работать над докладом, который он собирался сделать на следующий день.

Результаты (английский) 1:

though it was very late, he continued to work on a report that he was going to do the next day.

Результаты (английский) 2:

even though it was very late, he continued to work on the report, which he was going to do the next day.

Результаты (английский) 3:

although it was very late, he continued to work on the report, which he was going to do the next day.