前四周期的A、B、C、D四种元素在周期表中均与元素X紧密相邻．已知元素X最高价氧化物的化学式为X₂O₅，B、D同主族且B元素的原子半径是同族元素中最小的，C的最高价氧化物对应的水化物是强酸．

下列关于多细胞生物体细胞分裂和分化的叙述中，错误的是（  ）

填填记记

银杏树又叫____树和____树，如果你小时候种下一棵银杏树，一直要等你当上____，才能吃上它的果子。

    These are Cara and Ben. They are twins (双胞胎). They are twelve. This is their bedroom. It's a nice room. There are two beds in the room. The yellow bed is Cara's and that green one is Ben's. The twins have one desk and two chairs. The chairs look the same. Cara's sweater is on his bed. Ben's coat is on his chair. Their clock, books and pencil-boxes are on the desk. Their schoolbags are behind the chairs.