dm. Designated Marksman. military marksman role in a U.S. infantry squad. The DM's role is to supply rapid accurate fire on enemy targets at ranges up to 870 yds with a highly-accurate semi-automatic rifle equipped with a telescopic sight.he DM's role is to supply rapid accurate fire on enemy targets at ranges up to 870 yds with a highly-accurate semi-automatic rifle equipped with a telescopic sight.
The average person is awake for about 14 to 16 hours per day. Most could extend that to about 20 hours if they were to stay up later; up to 40 hours is easy once a person gets beyond the 24 hour mark; longer than 60 hours (staying awake straight through two nights and three days) is rare, but doable; the record is 264 hours or 11 days straight. Hannah Griffiths.
Randy Gardner holds the scientifically documented record for the longest period of time a human being has intentionally gone without sleep not using stimulants of any kind. Gardner stayed awake for 264 hours (11 days), breaking the previous record of 260 hours held by Tom Rounds of Honolulu. LCDR John J. Ross of the U.S. Navy Medical Neuropsychiatric Research Unit later published an account of this event, which became well-known among sleep-deprivation researchers.