Certainly! Here are the completed sentences with the appropriate articles filled in:

### A
1. We had **a** really good science lesson at school today.
2. I found **an** unusual insect on the wall outside our house.
3. It’s your birthday next week. Are you going to have **a** party?
4. We waited for hours, but we finally saw **the** Queen.
5. Why don’t we listen to **the** radio?
6. Have you got **a** euro I could borrow?
7. Mum has gone to **the** bank, but she’ll be back soon.
8. Where have you been? I’ve been waiting for over **an** hour!

### B
1. I had (1) **a** really bad day on (2) **a** Tuesday.
2. I bought (3) **a** new game on CD-ROM for my computer, but (4) **the** game didn’t work properly. I took it back to (5) **the** shop on (6) **North Street**, but (7) **the** manager blamed me! He pointed to (8) **a** scratch on (9) **the** CD-ROM and said I’d done it. I couldn’t believe it! I had to buy (10) **a** new one!

If you have any more questions or need further assistance, feel free to ask!