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

－_____ the beginning of June.[ ]

A. Behind

B. Since

C. Among

D. At

锦江之星旅馆有限公司的主要业务是（）经济型连锁酒店。

A.注册

B.开发建造

C.经营

D.管理