a farmer has some pigs and some ducks.there are 9 headsand 26 feet.有猪多少
问题描述:
a farmer has some pigs and some ducks.there are 9 headsand 26 feet.有猪多少
答
四
a farmer has some pigs and some ducks.there are 9 headsand 26 feet.有猪多少
四