What does the prefix pro- mean in the word prologue?

1.the hosts on two opposing mountains stood,  

2.thick as the foliage of the waving wood;  

3.between them an extensive valley lay,  

4.o'er which the gleaming armour pour'd the day,  

5.when from the camp of the philistine foes,

6. dreadful to view, a mighty warrior rose; in the dire deeds of bleeding battle skill'd,

different routes can lead to sammy to different places, with different roads.   if you check a map, you can see the routes.   try to make connections of the places and count how many there are.   hope this : )