麻烦帮忙改一下这个句子的时态,我很晕了.

题目

麻烦帮忙改一下这个句子的时态,我很晕了.
I went to a big music center here at Xiamen to work as an sales assistant for 10 days.We sell pianos and I got to know a lot about a variety of brands of pianos and gained the experience of dealing with costomers.(I made few mistakes in the time tense in this paragraph i think)
中文的意思是说,我之前有去一个厦门的音乐中心当销售助理,我只去了10天.我在那里销售钢琴,了解了很多钢琴品牌,也学会了如何接待消费者.

答案

供参考
I went to a big music center here at Xiamen to work as an sales assistant for 10 days.It sells pianos and when I worked there I got to know a lot about a variety of brands of pianos and gained the experience of dealing with customers.
该厦门中心目前仍应卖琴,所以这里用现在式(sells)
之后附加when I worked there
便将时态带回过去式
免了混淆
你看这样处理可否接受