There was a quiz-posting on Facebook that I wasn't sure to pick the answer:
Choose the more probable!
'Urgh! The lecture __ for three hours and it was super boring.'
A) dragged on
I've done a quick-search on my vocabulary book and found these examples:
This film lasts for three hours.
The meeting went on/dragged on for two hours. (suggests longer than expected or desired)
Now, I still can't see the difference since they both use for. Since the question (above) itself instructed to choose the more probable, is it probably A? It's stronger according to my book. However I'm still thinking, why isn't B? What's the difference?