Голоса их были слышны, но нельзя бы

Голоса их были слышны, но нельзя было разобрать , о чем они говорят.

В половине седьмого аэропорт все ещё был открыт, но все его службы работали с огромным напряжением.

Результаты (английский) 1:

Their voices were heard, but it was impossible to make out what they are talking about. Half of the seventh airport still was open but all its services worked with enormous stress.

Результаты (английский) 2:

Their voices were heard, but could not make out what they were saying.

At half past six the airport was still open, but all his life worked with great effort.

Результаты (английский) 3:

their voices have been heard, but couldn't make out what they say.at half past six the airport was still open, but all of his stations worked with great intensity.