—What were you doing when the UFO arrived?— I with my dog on the street.
| A．walked | B．was walking | C．is walking | D．have walked |
–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 |
Nobody can stop me ____ working hard at English.
| A．for | B．on | C．from | D．in |