【单选题】

The flying fox is not a fox at all. It is an extra large bat that has got a fox’s head, and that feeds on fruit instead of insects. Like all bats, flying foxes hang themselves by their toes when it rest, and travel in great crowds when out flying.

A、group will live in one spot for years. Some- times several hundreds of them occupy(占据) a single tree.As they return to the tree toward sunrise, they quarrel among themselves and fight for the best places until long after daylight.
Flying foxes have babies once a year, giving birth to only one at a time.At first the mother has to carry the baby On her breast wherever she goes. Later she leaves it hanging up, and brings back food for it to eat. Sometimes a baby falls down to the ground and squeaks((尖叫) for help. Then the older ones swoop (俯冲) down and try to pick it Up. If they fail to do so, it will die. Often hundreds of dead baby bats can be found lying on the ground at the foot of a tree.
The passage tells us that there is no difference between the flying fox and the ordinary bat in______.
A、their size
B．their appearance
C．the way they rest
D．the kind of food they eat