如图是某草原生态系统中部分生物之间关系的示意图，请据图回答：

地面某个地点高出海平面的垂直距离叫____，某个点高出另一个地点的垂直距离叫____．

阅读古诗《观沧海》，完成小题。
                                                                                                观沧海
                                                                                                  曹操
                                                                                       东临碣石，以观沧海。

                                                                                       水何澹澹，山岛竦峙。

                                                                                       树木丛生，百草丰茂。

                                                                                       秋风萧瑟，洪波涌起。

                                                                                       日月之行，若出其中；

                                                                                       星汉灿烂，若出其里。

                                                                                       幸甚至哉，歌以咏志。