Question

What might have been one advantage of walking completely upright

Answer 1

It's probably the major advantage of walking upright was that it freed the hands to use tools and carry all the pray.

Step-by-step explanation:

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Answer 2

Probably the major advantage of walking upright was that it freed the hands to use tools and carry (the pray).

Another advantage is seeing further than on four legs, without the need to stop walking and raising oneself for a little while to look around ( like some animals do).