From the original critics about Dr Chen's use of English at a meeting, it was said that the majority of the audience can understand the Chinese. So I guess in that case, it would be better to give the talk in Chinese.

I indeed have had an embarassing experience, i published a review paper in Acta Botanica Sinca withthe aim to help Chinese colleagues to understand a method which is largely used abroad, but much misused in China. The journal published papers in English. the problem is that not many Chinese colleagues can understand that paper with difficulty with English, it attacts more foregin citations than home ones.

So I wonder China may need to have good quality journals which publish in Chinese, and have English edition of selected papers.