浓硫酸和浓盐酸敞口放置一段时间后，其溶液中溶质的质量分数(  )

阅读下面这首古诗，完成两题。
                                                                                                      赋得古原草送别
                                                                                                         唐 白居易
                                                                               离离原上草，一岁一枯荣。野火烧不尽，春风吹又生。
                                                                               远芳侵古道，晴翠接荒城。又送王孙去，萋萋满别情。