呼吸系统中的哪个结构特点与进行肺泡与血液内的气体交换无关

下列对本文内容理解不正确的一项是(    )

    Once, in a small village, lived a family with eight children. Two of the children loved1very much, but the family was so poor that2was impossible to send them to study at the art college at the same time. After many discussions, the two boys finally3a plan. They would throw a coin. The loser would4down into the coal mines (煤矿) and used the money that he would make in the mines to support his brother5at the college. Then, when the brother who won finished his studies, after four years, he would support6brother studying at the college.

    James won and Jack went down into the mines. James studied with all his heart and his paintings were much better than7of most of his teachers, and by the time he graduated, he was beginning8a lot of money for his paintings.

    9James returned, the family held a big dinner for his great success. Soon after the meal began, James 10up from his seat to drink a toast(敬酒) to his dear11 He said, "Jack, now you can go to the art college and your dream 12true. I will take care of you."

    But Jack said13 "Brother, the four years in the mines has done too much to my hands, so it's too late. Now I can't even hold a glass. "

    To show his great love and respect, James drew his brother's hands 14fingers towards the sky.

    He called his drawing "The Praying Hands", 15 became very famous years later.

在不透明的袋子中有黑棋子10枚和白棋子若干（它们除颜色外都相同），现随机从中摸出10枚记下颜色后放回，这样连续做了10次，记录了如下的数据：

根据以上数据，估算袋中的白棋子数量为（　　）