5. We wish to keep your fully informed on this matter.
我们希望就此事以后经常保持联系。
还能这样说：
We wish to keep you fully posted on this matter.
We hope you can keep in touch with us to talk about this matter.
应用解析：
put the matter right 拨乱反正；
take matter easy 泰然处之；
bring the matter 注意这事件；
let the matter go 让这件事过去

6. You should try your best to sell all the products.
你应该尽力卖掉所有产品。
还能这样说：
You should sell all the products as possible as you can.
You should spare no efforts to sell the products.
应用解析：
be sold on sth./sb. 看中某物/某人；
例如：
I like the house but I am not sold on the place.
我喜欢这所房子，但相不中这个地区。

7. We intend to expand our business to foreign countries next year.
我们打算明年把业务拓展到国外。
还能这样说：
It is our intention to expand our business to foreign countries next year.
We plan a global business to sell our products next year.
应用解析：
expand in/into 把……扩展；
expand on 细说，阐述

8. How are you getting on with the work?
工作进行得怎么样？
还能这样说：
How is your job going?
How is your job coming along?
应用解析：
get on的意思是进展；出人头地；上车。
例如：
He is sure to get on in the world.
他一定会出人头地的。