What are three anatomical features that birds share with their theropod ancestors

Three anatomical features that birds share with their theropod ancestors are:
1. they had light, hollow bones
2. they rearranged hip and leg muscles because this of improved bipedal movement
3. they had their flight oriented with the use of wings for balance

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Ibelieve the answer is relative humidity  because it makes more sense that way. solar flares usually occur in space it doesn't affect the earth, well it could but it wont make a significant damage.  latitude is land it doesnt do anything. prevailing winds, i dont know the correct meaning for this but i doubt that affects the land so it has to be relative humidity.