在电子商务中，物流服务 包括商流服务。
参考答案：错
It’s difficult to ___ these old books for some of them ______ none of the classification.
A．look for; are belonging to
B．put up; belong
C．sort out; belong to
D．pick up; are belonged to
青少年每日蔬菜的总供给量约为（）。
A.800g
B.700g
C.600g
D.500g
E.400g
