How to translate „never seen before“ into chinese?

Is this translation correct? My chinese teacher asked me to make a presentation on how I learn Chinese. Translation: 我的中文老师让我做一个如何学习中文的演讲。

提高中文水平 Could you please correct. 你知道,我仍然有我的发音问题。我忘记了很多单词。 我认为，为了提高我的水平中文，我一定要多讲。 所以我准备了一些问题. 因此我可以练习我的口语和理解. You know that I still have problems with my pronunciation; I forget a lot of words. I think that in order to improve my Chinese, I must speak more. I prepared some questions, so I can practice speaking and understanding Chinese.

difference between准备 and预习 你好, what ist the difference between准备 and预习? They all mean prepare. Which of the following sentences is correct? I prepared some questions. 我准备了一些问题. 我预习了一些问题 I prepared this text 我准备了这个课文 我预习了这个课文

translating the verb „to stop“ 你好. I have problems translating the verb „to stop“ into Chinese. As always I find a lot of translations in a dictionary. Could you please translate? I will stop learning Chinese. I stopped the car. Stop doing that. I am grateful for any other examples.

Could you please translate these sentences into chinese: Could you please translate these sentences into chinese: I will tell you what I did. Could you tell me what that means? Let me know what you will do during your holidays

我的工作. 我在公司XXX工作。 我们正在开发和制造使玻璃瓶生产控制系统。 我是一个工程师电气。我工作在销售。 我拜访我们的客户遍布世界各地。 我解释我们的控制系统的技术细节。 当客户订单的控制系统，我从一开始到结束做的工程 规划。 我喜欢我的工作：技术工作和人接触的混合物。 I work in the company XXX. We are developing and manufacturing control systems for machines that make glass bottles. I am an electric engineer and work in the sales. I visit our customers all over the world. I explain the technical details of our control systems. When the client orders a control system, I do the project planning from the beginning till the end. I like my job: a mixture of technical work and human contacts.