I believe it is the compass. It aided sailors locate the direction to which they needed to go. Even before the age of exploration, people had ships capable of long voyages. As the years pass, the designed improved to an extent that they can travel farther.
Answer:
A speaker should practice going through the entire speech at least four times over a course of several days.
Explanation:
Grendel attacks Heorot and devours the first warrior he encounters, when he tries to grab the second warrior, Grendel is shocked when the warrior grabs him back with great strenght (by the time the reader discovers this warrior was actually Beowulf).
