399840≈____万         50499872000≈____亿

998900000≈____亿      4042756800≈____亿

下图为印度半岛某城市示意图。据此回答下面小题。

阅读下面一首诗，回答后面问题。
                                                                                                           待储光羲不至
                                                                                                                 唐 · 王维
                                                                         重门朝已启，起坐听车声。要欲闻清佩，方将出户迎。
                                                                         晚钟鸣上苑，疏雨过春城。了自不相顾，临堂空复情。
【注】要欲：好像。了自：已经明了。空复情。自多情。