问题详情

A．milk, meant, vegetables, etc. were delivered
B．it has promoted the sales of many kinds of commodities
C．a new, economical way to preserve food
D．most kids like iced soft drinks
E．something every housewife needs
F．produced by the fridge when it is working
Before fridges came into use, it was still possible for people to have fresh foods because______.请帮忙给出正确答案和分析，谢谢！