Yes, you can select several pulses and look at the results from all of them at the same time. If a certain question has been asked on different occasions and in different pulses you’ll still be able to see the trend for the question.
You can also use this feature if you want to look at, or export results from two different pulses asked on the same week.
Tip! If you can't see several pulses, try to extend the selected period on the timeline (under When) to make sure that it covers the weeks when the pulses were sent.