–What do you call this in English?
–It’s stamp. It is used ____ sending letters.

Hainan celebrated（慶祝）her twentieth birthday ____ April 26,
2008.   
A. in   B. at   C. on

We have been in No. 7 Middle School ____ three years.    
A. since   B. in   C. for

–How do you travel to school every day? –I go ____ bus.   

–How do you learn English so well?   
–____ chatting with my uncle in America online.

We looked at each other ____ surprise when we heard a bird
singing “Happy birthday to you”.

It’s rather cold in most of South China ____ in spring.

This photo reminds me ____ the days when I worked ____ the
farm with my classmates.

Peter usually gets up early ____ the morning.            

You must ride your bike ____ the right side of the road.