Rollo was a viking leader who settled in normandy. truefalse

Its true that Rollo was a Viking leader who settled in Normandy.Rollo is first recorded as the leader of these Viking settlers and he continued to reign over the region of Normandy. Rollo emerged as the outstanding personality among the Norsemen who had secured a permanent foothold on Frankish soil in the valley of the lower Seine.

None   they are   equally likely to occur on any plate boundary

Sonar is an application of the doppler effect used by submarines.  this test was on k12.