—How often do you clean your classroom? —_________．

A．Last week B．In the afternoon C．For ten minutes D．Every day

——How often do you clean your classroom?

——______.

[　　]

A. Once a week　　B. Every week

C. Each week　　  D. One time a week 

-“How　 do you clean your classroom?"

-“Once a week.”

A. long B. often　 C. much D. soon