We all ______ the summer vocation _____ a time for study, but she has a different idea.

A．view…as

B．see… as

C．regard… as

D．all of above

经济订货批量（economicorderquantity，EOQ）是指年总存货成本最小时的每次订货批量，EOQ随着存储费用增加而增加。