A:植物细胞在b段形成赤道板,向四周扩展,将细胞一分为二
B:c段结束核DNA含量增加一倍
C:c和d为一个细胞周期
D:核遗传物质的平分一般发生在b、d段
已知数列a1,a2,a3,a4,a5的各项均不等于0和1,此数列前n项的和为Sn,且满足2Sn=an-a2n1≤n≤5,则满足条件的数列共有( )
—I am really struck by your spoken English. You speak so fluently. Have you been abroad?
—Yes. I ______ in London for two years.