You didn't understand the question yet
.
You need to improve your understanding in English objectively rather then grammatically
The Argument is all about
"Oil Cleaning Method used in China, irrespective they are HAN or Not. Still they are Chinese.
lol, you need to understand your country / culture first dude,
A) My native language is Hindi
B) I used Slang in English, as i am doing multi tasking things and this PDF is non-priority posting, it is highly possible that he didn't understand slang / shot language form, which is evolved over the period of time.
You are still at 1st Gen level of English, and english is far more complex and changes region to region.
He still not able to figure it out, what is the argument is all about, which shows the level of understanding in English.