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.
TIME reported that the was found dead in his sleep. Because of the time difference between Europe and China, soccer matches didn't begin until the middle of the night, between 1 and 3 a.m. In closely-watched experiments, people have been able to stay awake for eight to 10 days straight, Scientific American reported. They didn't suffer any serious health effects, although they did have severe problems with concentration, perception and the like the longer they were awake.