—_________do you see a dentist?
—Once a month.
| A．How soon | B．How long |
| C．How much | D．How often |
–How do you learn English so well?
–____ chatting with my uncle in America online.
| A．For | B．By | C．In | D．With |
–How do you travel to school every day? –I go ____ bus.
| A．on | B．at | C．in | D．by |
We have been in No. 7 Middle School ____ three years.
A. since B. in C. for
Hainan celebrated（庆祝）her twentieth birthday ____ April 26,
2008.
A. in B. at C. on
–What do you call this in English?
–It’s stamp. It is used ____ sending letters.
| A．for | B．to | C．with | D．by |