In the first session of the morning, the teacher walked up to the podium with a leather ball and said to everyone: Before today's class, I want to do two tests with you, and test everyone with two questions. Please listen up.

The teacher took one look at it, and everyone was ready to answer the question, so he took out the ball, threw it vertically to the ground, and bounced back. Then the teacher said: First, if the ball in my hand moves in free fall from a certain height, and its displacement in the first second is exactly equal to 1/4 of its displacement in the last one second, what is the height of the ball from the ground when it starts to fall? Time limit 30 seconds.

After hearing this, everyone quickly took out paper and pen to calculate. The Qiantang thrush was busy, but when she saw that the warbler was motionless, she hurriedly asked her why don't you count, hurry up and tell me the answer. Liuying smiled and said, I have already calculated.

Qiantang Thrush couldn't help but be taken aback, and the Liuying quietly told her the answer.

The teacher looked at his watch and said, "Okay, it's time." Which of my classmates sued me?

Liuying thought to herself that it was better not to be so publicistic when she first came. Seeing that everyone was silent, the teacher looked around, stopped at Liuying and said, "That female classmate, please answer." Liuying said in her heart: How can you be so coincidental to others.

Liuying stood up and replied confidently: Teacher, it is 31.25 meters. The teacher couldn't help but be stunned for a moment, and then said happily: Your answer is correct! Have a seat.

The classmates couldn't help but be amazed, Liuying sat down with a smile, and her table mate Qiantangyu was even more surprised, why not close her mouth, and couldn't help but praise: Liuying, you are so amazing. The warblers are a little embarrassed.

The teacher replied: "Everyone's table is very good just now, and there is another question next, this question is more difficult, I will give you three minutes to calculate, please listen."

A person is 20 m away from the rear of the bus, running towards the car at a constant speed of v=6m/s, and at the same time, the car starts from a standstill with an acceleration of 1m/s2 and moves in a straight line with uniform acceleration. Can you catch up with the car? If so, how long will it take? If not, what is the minimum distance between him and the car?

Everyone took out a pen and paper and nervously calculated, and the Qiantang thrush couldn't help but glance at the warbler again. I saw Liuying pouting, holding the tip of a pen to her lower lip and thinking hard, after half a minute, she picked up the pen and scratched it twice on the scratch paper, and then put the pen down with a smile. Qiantang Thrush leaned over to look at it and asked suspiciously: "Wandering warbler, what are you paddling, why can't I understand it?" In the end, whether to catch up or not. Liuying winked her left eye mischievously and said: Classmate, there is still time, please calculate it seriously this time, okay.

Three minutes passed, and the teacher smiled and asked, "Have you all figured it out?" What is the result, who will answer me, please take the initiative this time.

A boy stood up and said loudly: "Teacher, I have calculated, that person can catch up and get into the car, it will take 2 minutes." The teacher smiled and motioned for him to sit down, and then said to everyone, "Do you have any different answers?" Everyone only saw each other and looked at each other, not sure enough.

Unexpectedly, the ignorant fire warbler raised her hand gently, and the teacher smiled and said to her: Liuying, do you have a different answer? The warbler got up and said, "Yes, teacher." There was no way that person could catch up with the car. The teacher asked: What about the reason, can you come up and write about your calculation process? The warbler nodded, walked up to the podium, and began to write as she spoke: Let's first draw a schematic diagram of the motion of a person and a car, and then assume that the speed of a person and a car is equal after t seconds.......

Liuying wrote the whole calculation process on the blackboard, and the boy suddenly touched his head and sat down embarrassed. And the teacher also nodded with satisfaction, and everyone couldn't help but marvel at what a smart and beautiful girl Liuying was.

Liuying returned to her seat, and Qiantangyu praised her and said: Liuying, you are really amazing! I've never seen a girl study physics so well, even the boys in the class are not as good as you. Liuying thought to herself: I've always liked physics, and besides, I used to be a boy, so it's not strange to me.

Soon the bell rang for the end of class, and the physics class was over. The warbler was sorting out the books, and the Qiantang thrush came over and said to the warbler: "Warbler, let's go to the bathroom together." Liuying was frightened, her face suddenly turned red like an apple, and she replied in a slurred manner: "Shrimp?!" ....... I ....... you that? Qiantangyu said, "Let's go to the bathroom together, what's wrong with you, beauty, are you uncomfortable?" The warbler hurriedly replied: No, no...... I realized in my heart that I'm a girl, so there's no problem. Qiantangyu happily pulled her up, then took her hand and said, "If it's okay, then let's go." ”

Walking in the aisle leading to the bathroom, the warbler suddenly remembered the incident in Eastern Siberia:

The warbler opened his eyes and found himself lying in a hospital bed. Sister, you've finally woken up! She heard a familiar voice, it was really Sister Shiranui Mai. Sister Mai sat on the edge of the hospital bed with tears of joy and looked at herself.

Her lips were dry, and she asked her sister slowly in a somewhat surprised tone: "Sister, who do you call sister, what's wrong with you?" Suddenly, she felt that the voice she was coming out did not have the strong and deep feeling of a man, but was replaced by a shrill and delicate voice. She felt that something was wrong, so she wanted to get up, only to find that she was covered in bandages. She tried desperately to get up, but she felt that her body was in pain and she couldn't do it. I don't know that Huo Wu couldn't help but shed tears secretly when she saw her like this. Liuying begged her sister and said: Sister, what happened to me, can you please sue me? Shiranui Mai brought a mirror and put it in front of the warbler. She was shocked......

In the mirror is the face of a sweet girl with black hair! She screamed loudly in fear, and the mirror in her hand fell to the ground.

Younger sister! Listen to me.

"Liuying, you are doing well today, keep up the good work." The warbler woke up from her memory and found that it was the physics teacher who walked by and praised herself twice. She hurriedly bowed to the teacher.

sent the teacher away, and looked back to say that although there was no physical problem, Liuying's psychology has not completely changed, so she walked a little slowly.

Qiantang Thrush asked curiously: "Wandering warbler, what's wrong with you?" Liuying hurriedly replied: Oh, it's just that I'm not used to ...... with girls Let's just go to the bathroom together. Chido Thrush was curious again: Is it because the habits of your Tokyo universities are different? The girls on our side go to the bathroom together after class, and take a walk together to relax and chat.

The warbler said, "So that's so." The thrush replied, "Yes, you'll get used to it soon." By the way, tell me about the high schools in Tokyo and whether the students there are doing very well in their studies. Liuying thought for a while and said: It's okay, maybe it's all the same. Chido Thrush turned to say: Are there a lot of handsome guys in Tokyo universities? Liuying thought to herself that this guy is really a nymphomaniac, if I count, then there are really a lot. She replied, "You, you know the handsome guy." People didn't pay attention to that. Qiantangyu smiled and said: Girls like handsome guys, but you only know how to read books. But you're so good-looking, do you have a boyfriend? Liuying thought to herself that this was really nothing, and she said: You, don't gossip, I won't tell you. Qiantang Thrush giggled: I saw that you were embarrassed, so I let you go. Oops, the bathroom is here, let's get inside.

They came to the door of the women's bathroom, watching many sailor suit beauties constantly coming in and out, Liuying suddenly blushed, and turned her head as if she was about to leave, Qiantang Thrush pulled her and said: Beauty, where are you going again. Let's go in together. Liuying's face was hot, and she was pulled into the women's bathroom by Qiantang Thrush with her head down......

When the warbler came out, the Qiantang Thrush had been waiting outside for a long time, and she complained: Why have you been so long? Uncomfortable? Liuying hurriedly said: There are no paper towels in the bathroom in that ....... just now, so I will come out and find someone to borrow them. Qiantangyu said, "Let's go back to the classroom."

Liuying nodded, and secretly exhaled, thinking that it is not easy to go to the bathroom at school, but it is easy if it is at home.

Soon the day's classes were over, Liuying and Qiantangyu packed their schoolbags and prepared to leave the classroom, Qiantangyu said to Liuying: Liuying, are you far away? Liuying said: It's a little far. Qiantangyu asked: Then you don't live on campus? Liuying replied: Live, but I just transferred to another school, there are a lot of things to do, and the dormitory has not been determined, so I don't live for the past two days, and I have a car to pick me up at home. Qiantangyu picked up his schoolbag and said goodbye to the warbler: Oh, then I'll go back to the dormitory first, and I'll see you tomorrow. Liuying replied with a smile: "See you tomorrow, Qiantang-san."

As soon as Qiantangyu walked to the door of the classroom, he suddenly turned around and said to Liuying: Liuying, there is a tennis class tomorrow afternoon, don't forget to bring a tennis skirt. Liuying was frightened for a moment, thinking that she didn't remember such a thing at all, so she picked up the phone and called her sister as she walked, asking her sister to hurry up and buy it for herself.