UNDATED (AP) — Pot smoking has become more of habit for U.S. college students than cigarette smoking is.

That's what researchers at the University of Michigan are saying.

Their study says pot supplanted cigarettes last year as the smoke-able substance of choice among full-time undergraduates who light up regularly.

Just under 6 percent of full-time students surveyed said they had used marijuana at least 20 times in the previous 30 days.

By contrast, 5 percent of those surveyed indicated they had smoked cigarettes that often.

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