有一对兔子，从出生后第3个月起每个月都生一对兔子，小兔子长到第三个月后每个月又生一对兔子，假如兔子都不死，问每个月的兔子总数为多少？-There is a pair of rabbits, from third months after the birth of every month for a rabbit, the rabbit grow up to third months after each month and a pair of rabbits, if the rabbit wil