On the way ___a book,he found some of his classmates__in the street.On the way _______a book,he found some of his classmates_______in thestreet.A.to buy; knocking downB.to buy; knocking aboutC.to buying; knocking aboutD.to buying; knocking into
问题描述：
On the way ___a book,he found some of his classmates__in the street.
On the way _______a book,he found some of his classmates_______in thestreet.
A.to buy; knocking down
B.to buy; knocking about
C.to buying; knocking about
D.to buying; knocking into
答