5. Could you tell me how much it is?
你能告诉我这个多少钱吗?
还能这样说：
Would you mind telling me how much it is?
Would you tell me how much you charge for it?
应用解析：
admission charge 入场票价;
advance charge 预付款;
after charge 附加费率
6. There is no price tag on it.
这个上面没有价签。
还能这样说：
The price is not marked.
I can't find the price tag on it.
应用解析：
keep a tag on 检查;监视;记录;
tag along 尾随，紧紧跟随;温顺地陪着;
tag oneself on to(未经同意或邀请)硬跟着，缠着;
tag, rag and bobtail 乌合之众，下层人民，衣衫不整的人们
7. Is there a discount on the computer?
这台电脑打折吗?
还能这样说：
Any discount on the computer?
Can you give me some discount on the computer?
应用解析：
computer graphics 电子计算机制图;
computer language 电子计算机语言;
computer dating利用计算机安排单身男女约会的服务
8. Buy one, get one free.
买一送一。
还能这样说：
Buy one give one.
Choose one and the second is free.
应用解析：
for free 免费的，无偿的;
get free 摆脱……获得自由，获得解放;
make sb. free of 给予某人分享……的权利，让某人有权进入……
free out of 从……放出来
as wise as an owl 非常聪明