防火间距应从距建筑物最近的储罐外壁算起，但防火堤外侧基脚线至建筑物的距离不应小于（）m。

A.5

B.10

C.15

D.20

— How long has the nationwide ban (禁止) on plastic bags been put into practice? 

—             the beginning of June. [ ]

A. Behind

B. Since

C. For

D. At