图A表示细胞进行有丝分裂的一个细胞周期所用的时间，图B表示连续分裂的细胞相邻的两个细胞周期图．下列叙述中，正确的是（　　）

①一个细胞周期是指乙→乙的全过程

②在高等植物细胞内，两组中心体之间发射出星射线形成纺锤体发生在甲→乙过程

③c、d两段都要消耗ATP

④b段的主要变化是DNA的散乱分布于纺锤体中央及有关蛋白质的合成．

阅读理解

    Turn left at the second crossing if you drive along Center Street north to south. If you come by bus, you can get off(下车) at the B. Street Bus Station. You can't miss it!

    Please come to the black door. Our party will be on the farm behind the house. Put your gifts into the small tent on the grass(草地). Remember : This is a surprise party, so do not let him know anything about it by the party.

    We will have a buffet lunch(自助餐) and later all kinds of interesting games for everybody!

    Music Show at 4 P.M.

    Bring your guitars, violins, drums and anything that makes sound！

    Please let me know by July 4^th if you can make it.