你有销售经验吗？
Have you got any selling experience?

For example:
A: Have you got any selling experience?你有销售经验吗？
B: I worked in a department store in a small town last summer vacation.
去年暑假我在一家百货公司工作过。

关于本公司的产品和市场份额,你知道些什么？
What do you know about our major products and our share of the market?

For example:
A: What do you know about our major products and our share of the market?
关于本公司的产品和市场份额，你知道些什么？
B: Your company's products are mostly marketed in Canada and the United States, but particularly have sold very well here in China.
贵公司的产品主要在加拿大和美国市场销售，但在中国市场的销路也已经非常好。

我想将来你会发现中国也是一个容易赚钱的市场。
I think in the future you will find China to be a profitable market as well.
profitable (adj.)有利可图的

你认为对一个销售员来说最重要的是什么？
What do you think is the most important qualification for a salesperson?
What do you think is the most important requirement for a salesperson?
What do you think is the most important asset for a salesperson? 

For example:
A: What do you think is the most important qualification for a salesperson? 你认为对一个销售员来说最重要的是什么？
B: I think it is confidence in himself and his products.
我认为是对他自己和对他产品的自信。

你都学过什么课程？
What courses have you completed?

For example:
A: What courses have you completed?你都学过什么课程？
B: The courses I completed are marketing, business law，business English，statistics，marketing principles, sales management, distribution theory, economies and psychology.
我学过的课程有市场营销、商业法、商务英语、统计学、市场原理、销售 管理、销售原理、经济学和心理学。

我想随着我在销售和市场方面经验的增加，我的目标会变得越来越明确。
I think my goals will become clearer as I gain experience in sales and marketing.