下列少数民族中，人口在400多万以上的是（   ）

阅读下面诗歌，回答（1）～（4）题。

麂子

牛汉

                                                                                                                       远远的

                                                                                                                       远远的

                                                                                                                       一只棕红色的麂子

                                                                                                                       在望不到边的

                                                                                                                       金黄的麦海里

                                                                                                                       一蹿一蹿地似飞似飘

                                                                                                                       朝这里奔跑

                                                                                                                       四面八方的人

                                                                                                                       都看见了你

                                                                                                                       用惊喜的目光

                                                                                                                       用赞叹的目光

                                                                                                                       用担忧的目光

                                                                                                                       麂子

                                                                                                                       远方来的麂子

                                                                                                                       你为什么生得这么灵巧美丽

                                                                                                                       你为什么这么天真无邪

                                                                                                                       你为什么莽撞地离开高高的山林

                                                                                                                        五六个猎人

                                                                                                                        正伏在草丛里

                                                                                                                        正伏在山丘上

                                                                                                                        枪口全对着你

                                                                                                                        哦，麂子

                                                                                                                        不要朝这里奔跑

已知a、b、c分别为Rt△ABC（∠C=90°）的三边的长，则关于x的一元二次方程（c+a）x²+2bx+（c-a）=0根的情况是（　　）.

以下最能说明生命宝贵性的是（    ）

①生命无价的                ②地球因生命的存在而变得生机勃勃

③生命是独特的            ④生命属于我们只有一次

 下图为显微镜下观察洋葱鳞片叶表皮细胞临时装片的几个视野．请据图回答问题：