I should apologize to you for failing to visit you last week, but I've been very busy_____ the past few months.

A．since

B．before

C．among

D．over

零售业务的店面经营面积(不含库房)应不少于()，其店面内不得设有生活设施．

A．30m2

B．40m2

C．50m2

D．60m2