@viva_zhao Sorry for late reply. Yes, your idea matched my mind but when you discuss with our countrymen, you will see that some of them in this forum usually think short and do not understand the whole meaning of your sentences so they usually lead to another topic and this make us be far the main topic. This is clear when I saw the discussion between you and Viva_Viet, he was not awareness of your idea and some reply of him did not criticize your main point completely. We can base on the fact to persuade people, but people who do not think the opponent’s idea thoughtfully, it will be to hard to do so. The world should need open-minded people, not nationalists.