如图所示，用20分度游标卡尺测量钢球的直径时，符合规则而又科学的读数应为（   ）

阅读文段，回答问题。

  一位高三年级的女孩刚锁上宿舍的门，准备去教室，她的姐姐急冲冲地跑来，递给她一盒生日蛋糕，说：“过两天就是你的生日，我本想到那天给你搞个生日晚宴，可单位让我出差，晚宴搞不成了。”女孩把那盒蛋糕从窗口放到了靠窗的一张床上。

晚自习后，女孩回到宿舍，见七八个同学有说有笑，而且每人手里都拿着一块蛋糕。猛然间，女孩想起了姐姐送来的那盒生日蛋糕，还没等女孩开口，床位紧靠窗户的那个女同学拉住女孩的手兴奋地说：“我太高兴了！居然有人知道今天是我的生日，特地给我送来了一盒蛋糕，那蛋糕上有漂亮的图案和字母，可惜你回来晚了没看到。”说着，那位同学又用牙签串起一块蛋糕送到了女孩的手中，急切地问：“我们都不知道蛋糕是谁送的，你最后离开宿舍，我猜你一定知道送蛋糕的是谁，告诉我，这个人是男的还是女的？”这时候，有人恶作剧地说：“你那么丑样，哪会有男孩喜欢你！”

女孩真想说出这蛋糕是她姐姐送给自己的，可是，看着一张张兴高采烈的脸和那位错以为别人给送蛋糕的同学期待的目光，女孩不忍心让大家扫兴，更不忍心让那位同学尴尬，于是女孩将错就错撒了一回谎：“是一个很英俊的男孩！”众人一齐鼓掌：“一定是那个男孩爱上你了！”那位同学的脸上绽放出了灿烂的笑容。

熄灯以后，那位同学悄悄俯到女孩的耳根问：“那个男孩是不是我们班级的？你认识他吗？”女孩只好说：“天色暗，我没看清他的脸。”

以后的几天，宿舍里的中心话题都离不开给那位同学送蛋糕的神秘的男孩，虽说谈不出什么结果，但那位同学的脸上始终溢满了快乐，而且，她学习更用功了，她在期待着那位“白马王子”的出现。

毕业前夕，女孩见那位同学的头发上扎上了一条粉红色的绸带，女孩知道那条粉红色的绸带正是缠在姐姐当初送给她生日蛋糕盒的那一条。女孩真想把实情告诉她，可话到嘴边又咽了下去。那位同学表露的那份怀春少女特有的梦幻般的期待，让女孩深受感动，女孩决定继续将错就错，让她带着甜蜜的梦幻走向新的生活。

并非所有的错误都让人扫兴，都会留下遗憾，有时候将错就错也能“错”出美丽来。

    One night, I wondered what it would be like if I only asked questions. I decided that no matter what anyone said to me the next day, I would reply only with 1.
    I loved to read about scientists and their discoveries, and I knew that scientists always started their research with a question. I hoped that I could become a scientist. Maybe by asking questions, I could train my mind to be 2.
I survived the morning easily. “Is there any egg?” I answered when my mother asked what I wanted for breakfast. “Is this seat taken?” I asked when my friend Mike asked where he was going to 3 on the bus.
    In the classroom, Mr. Black spoke slowly and clearly while I listened carefully. The problem had been part of my homework the night before. I wrote the answer on the board, “Could the answer be 361?”
Mr. Black smiled and nodded. I thought,“How did I 4 to get through that?” I almost laughed because asking questions really was starting to become a 5.
    I thought I had made it safely through the whole day, 6 what I had come to consider my experiment blew up at the dinner table when my dad asked me about my day. “What do I always do?” I replied.
My parents looked at each other. My father 7 again. “Well, I hope you went to school,” he said.
    “Uhhh … why would you think otherwise?” I asked. My parents exchanged another 8  and were becoming annoyed.
    “Do you think questions are a good way to train your mind to be active?” I asked.
    “It 9 the question,” said my father. “Some questions are asked for 10 information. Those are good mind-training questions. Sometimes, people use questions to get the other person to say something. Sometimes people ask questions to get someone to agree with them. Those questions don't really achieve anything.”
    “I guess my experiment didn't work,” I said, and I told my father about my 11.
    “I think it worked 12!” my father said. “You made a discovery, didn't you? What matters is that you have put your idea into practice.”