Прошло некоторое время, прежде чем

Прошло некоторое время, прежде чем они поняли, что ему нечего было сказать.

Результаты (английский) 1:

It took some time before they realized that he had nothing to say.

Результаты (английский) 2:

It was some time before they realized that he had nothing to say.

Результаты (английский) 3:

It has been some time, before they realized that he had nothing to say.