Use the correct prepositions at, in, on in the following sentences
1.Mozart was born ____ the eighteenth century.
2.It’s usually warm ____ October.
3.We don’t see each other very often, only ____ Christmas time and ____ the summer.
4.They don’t have lunch ____noon.
5.The students have a party ___ the end of the course.
6.Do you want to have a party ____ your birthday.
7.Summer begins ____ June 21st.
8.Do people go swimming ____ May?
9.Are you busy ____ the present time?
10.Do they have examinations ____ March?
11.Please return this book ____ couple of weeks.
12.The library has short hours ____ Friday.
13.What time does it open ____ Saturday mornings?