Li Hua,

I feel great honored to be trusted with your personal affairs. Here is some advices for you:

First of all, you should talk to your parents or let them know where your interest is. If they know what you really want to do in the future, they are possible to change their mind. Secondly, don't worry too many about them because too much anxiety may affect your studies. Besides, you can talk to your teachers and your best friends such that they can help you to persuade your parents.

Personally, what you want to major in and what profession you would like to enter in depend on your own interest because they were part of your life. I hope you can follow my own interest and realize your dream in end. 

Yours,

Wang Lei

橡皮密度测定主要是检查橡料是否混炼均匀，配合剂称量是否准确，是否错配、漏配。