The last issue of this volume is just around the corner,and the year’s work is almost complete.I do not know why I do not have much sense of achievement.Due to the sudden outbreak of COVID-19,I did not do many things I wanted to do.For example,I wanted to exchange ideas with leaders and colleagues at the publishing house in Beijing in order to improve the journal.All the original plans to go abroad were disrupted.To fight the virus,people traveled only when necessary.Over the past year,it is a great pity that some key arrangement contributions failed to come true.Fortunately,thanks to the joint efforts of my colleagues,this year’s editorial work will soon come to an end.