Danny is writing postcards ____his mother.
A. to B. on C. in
May I help you ___ it ?
A. to write B. write C. Both A. and B
We put the letter in ______ .
A. a postcard B. an envelope C. a stamp
I’m sending this letter ___ Shijiazhuang.
A. in B. to C . at
------ _____ postcards do you need? ---- Six.
A. How B. How many C. How much