What is risbi? First of all
Both water and food. However the most obvious answer would be water.
sunlight would be the answer to your question
The skeletal structures of both the bats and the humans developed from the same embryonic tissue for the main reason that both of these skeletal contains the humerus, radius, ulna, and the five digit bones. In addition, the main difference that these structures have is that the bat's wing is longer compared to the human arm.