因为 这句是被动语态
换成正常的语序应该是
I think my Uncle George took the photo.
你把它变成被动语态就是 I think the photo was taken by my Uncle George
而且照片是过去拍的,所以还是个过去式
只有照片被叔叔拍,你要是学B 就是照片拍叔叔,照片是没有那个能力的.