I am one of the lucky participants in a seven-day trip in Henan province. David Wang was our guide and I appreciated very much his polite attitude, take care to ensure our comfort and good mood, the competence with which he and local collaborators gave us all the information. He accompanied us both, during the daytime, during the visits, but outside the official program, to help us to spend an enjoyable time. I recommend him with warmth and I expect the next collaboration with him, certainly in next winter. Good luck in your work, David! Keep in touch! Petru (Romania)