800里面有80个十。

绘制图幅一样大的四幅地图，所选比例尺最小的是               (  )

如图，给出的是的值的一个程序框图，框内应填入的条件是（    ）

根据短文内容，选择正确答案。
A
    One day, Mr. and Mrs. White went shopping by car. They stopped their car near a store. They bought a lot of things and they wanted to put them in their car. But Mr. White couldn't open the door of the car. “Let's ask a policeman for help.” said Mrs. White. They asked a policeman to help them. The policeman was very friendly to help them open the door of the car. Just then a man came up and shouted, “What are you doing with my car?” Mr. and Mrs. White took a look at the number of the car. It was not their car.

在造血干细胞分化为B细胞的过程中，细胞内