将点B（5，－1）向上平移2个单位得到点A（a+b， a－b），则（      ）

    Doctors tell us that holidays are important. we should have a 1from work for a week or two weeks every year. If it is possible,we should 2our homes and go to another 3of the country. We should go away for 4Then, after the holidays, we will be 5and get ready for 6again.

    But some people do not want to leave their homes to 7in other places. They do not like a sudden change in their lives. They think their 8are best of all. And some people can have a rest in  9way. They can go to visit their friends. They can have a 10holiday together.

下列现象是细胞有丝分裂和减数分裂过程共有的是(　 　)
①DNA复制一次         ②着丝点的分裂             ③最终产生两个子细胞
④有同源染色体的分离 ⑤能进行非同源染色体自由组合 ⑥有染色体、纺锤体的出现