but some foreign pilots always use flight level no matter they are on standard or on QNH.
Not true,pilots when cleared to a Flight Level will use the terminology of FL rather than 'on standard'
When cleared to an altitude (below transition altitude) they will use the term altitude rather than the term on QNH.
The cleared altitude/flight level avoids also confusion of numbers when issued 'to' before the altitude or level.
Ie :call sign climb to 2700m ,is heard as climb 2 2700m.
So a more clear instruction would be:' call sign,climb to altitude 2700m' or 'call sign,climb 2700m'
I suggest ATC in china to read about the uk caa website on level bust/uk phraseology.
Proper phraseology in another step away from human error...
Oh and whats up with this continuous pilot use of 'AIRBORNE'
Whos teaching that???