----- Nội dung ảnh ----- Practice 3: Choose a word to complete the sentences 1. I think you'll find that the Microcar is really very (economic / economical) to drive. 2. I'm afraid we can only accept the return of the item if you still have the (receipt / bill). 3. If you show this coupon at the (checkout / discount), you'll receive a free gift. 4. I'm not keen on Justin Timberlake so I'll try to (refund / exchange) this CD for one by Blue. 5. This unbeatable special (offer / bill) is only available until the end of the week, so hurry! 6. I went back to the shop a week later, and the (price / cash) had gone up by 50%!