宋朝以来，没有做过我国国都的城市是( )。

A．开封

B．南京

C．杭州

D．洛阳

—You’re coughing badly，Martin. Why not give up smoking?

—Give up smoking？Easier said than done，Amy. Once you ______ the habit of smoking，it is very hard for you to ______.

A．keep up; break it away

B．take up; drop it out

C．pick up; get rid of it

D．build up; do away with it