The opening is good,but this sentence needs some work:
I first became interested in sales assistant. Because I am major in international economics and trade, and your company has the better reputation in the China market. I
The first sentence is incomplete- do you mean to join the two?
I first became interested in sales assistant because my major is international economics and trade
and your company has the better reputation in the China market
'better' is wrong; surely, it should be 'best', or 'finest'?
