Exercise 1: Điền các mạo từ “a/ an/ the” thích hợp vào chỗ trống 1.I bought __ blue sweater yesterday. 2. I’d like __ cup of tea. 3. There is __ apple and __banana on the table. 4. Mai has many books. ___ books are mostly about English grammar. 5. I took __ suitcase and __ backpack on holiday. ___ suitcase was much more useful. 6. Julie read __ book and __ magazine. She said ___ book was quite boring though. 7. She has __ black umbrella and I have ___ blue one. ___ blue one is bigger. 8. I bought __ new dress, but I was annoyed to find that __ zip was broken. 9. We should take __ taxi because it's getting dark. 10. I met __ very nice American last night. 11. __ sun rises in __ east and sets in __ west. 12. __ moon moves around __ earth. 13. We often play soccer in ___ afternoon. 14. ___ guitar is one of the most oldest musical instruments.