Dưới đây là các câu đã điền giới từ "in", "on", "at" vào vị trí thích hợp:

1. Tom isn’t here **at** the moment. He’ll be back **in** five minutes.
2. The course begins **on** 7 January and ends **on** 10 March.
3. Tom’s grandmother died **in** 1977 **at** the age of 79.
4. The price of electricity is going up **in** October.
5. Ann works hard during the week, so she likes to relax **at** weekends.
6. I can’t be at home **in** the morning. Can you phone me **in** the afternoon instead?
7. Jack’s brother is an engineer but he’s out of work **at** the moment.
8. **On** Sunday afternoons I usually go for a walk in the country.
9. Tom doesn’t see his parents very often these days - usually only **at** Christmas and sometimes **in** the summer for a few days.
10. The telephone and the doorbell rang **at** the same time.