I seldom see any with the four variants outlined in the original article. All four of such variations are acceptable. 1 could argue that they're far more appropriate than "Sincerely yours". Any of these could be a refreshing adjust from examining One more American kind letter. 心理账户：社交平台上“用华强北被同事识破”的社死现场，让不少人宁愿“吃土三个月也要买正品”。 If gravity bends https://goo.gl/maps/4n1J31u6uuphv4qV9