5. You can have another brand instead if you don't like it.
如果你不喜欢，可以换一个牌子。
还能这样说：
You can change it for another brand if you don't like it.
Another brand is allowed if you don't like this one.
应用解析：
a brand from the fire 幸免于难的人，从罪恶中被拯救出的人;
fire brand 火源;
brand sth. on sth. 在某事物上打烙印;
brand sb. as sth. 给某人加上污名;谴责某人
6. Can I help you?
有什么需要帮忙的吗?
还能这样说：
What can I do for you?
Is there anything I can do for you?
7. We provide free delivery and installation.
我们提供免费的运输和安装。
还能这样说：
The delivery and installation is free of charge.
You don't need to pay for the delivery and installation.
应用解析：
on delivery 交货付款;
abdominal delivery 剖腹产;
take delivery of sth. 收到某物
8. How long is the warranty?
保修期有多长时间?
还能这样说：
How long is the term of service?
How long does the warranty last?
应用解析：
under warranty 在保修期内;
product warranty 产品质量保证书;
long-term warranty 长期保修;
exceptive warranty 例外保证