题目

In China, many people are leaving the countryside to find jobs in the cities, because the countryside is much poorer than the city, and often there isn't much work there. Services such as hospital and transport （交通） are usually much better in the city than in the countryside. They hope that their lives will improve when they move to the city.     But in the big cities of Europe like London or Pads, people are moving out of the city. These rich families want to live a quieter life. They are tired of the noise and the dirt （尘土） of the city, and they are tired of the crowded st如图是某细胞有丝分裂示意图．请据图回答：（1）从图中可以看出这是 细胞的有丝分裂．（填动物或植物）（2）写出分裂期的细胞进行分裂的顺序： ．（用字母表示）（3）图 表示细胞分裂后期，此期染色体主要变化是 ．（4）图a是分裂的 期，此时细胞中有 条染色体， 条染色单体．（5）细胞的有丝分裂是将亲代细胞的 经过复制之后，精确地平均分配到两个子细胞中，保持了细胞的亲代和子代 的稳定性．可见，细胞的有丝分裂对于生物的 有重要意义．