The task of writing a history of our nation from Rome’s earliest days fills me, I confess, with some misgivings, and even were I confident in the value of my work, I should hesitate to say so. I am aware that for historians to make extravagant claims is, and always has been, all too common, every writer on history tends to look down his nose at his less cultivated predecessors, happily persuaded that he will better them in point of style, or bring new facts to light. Countless others have written on this theme and it may be that I shall pass unnoticed amongst them; if so, I must comfort myself with the greatness and splendor of my rivals, whose work will rob my own of recognition.
My task, moreover, is an immensely laborious one. I shall have to go back more than 700 years, and trace my story from its small beginnings up to these recent times when its ramifications are so vast that any adequate treatment is hardly possible. I shall find antiquity a rewarding study, if only because, while I am absorbed in it, I shall be able to turn my eyes from the troubles which for so long have tormented the modern world, and to write without any of that over-anxious consideration which may well plague a writer on contemporary life, even if it does not lead him to conceal the truth.
在x=-1处收敛，则此级数在x=2处的敛散性为（）。