Lingfeng castle, in the conference hall.

    "What is force? Force is the effect of an object on an object. For example, I now punch Sir Thorne..."

    "What you need to remember is that the forces between objects are interactive!"

    "What does that mean?"

    "Simply put, as long as one object exerts a force on another object, the stressed object in turn will certainly exert a force on the exerting object."

    "That''s why I punched Sir Thorne, but my own fist hurts. That''s why."

    "You should remember that a pair of interaction forces must produce and disappear at the same time..."

    "There are three elements of force. They are the size, direction and action point of force. They can influence the action effect of influence..."

    ……

    Two hours later.

    "Fire triangle, that is, the three elements of combustion, namely combustion supporting agent, combustibles and ignition source." Arthur pointed to the fire triangle pattern on the blackboard: "only if these three points are available at the same time, combustion can occur and last. Next, let''s take a look at an experiment..."

    With that, Arthur lit a small candle standing on the table. Then he picked up a valuable crystal cup and put it directly on the burning candle.

    Under the gaze of the people, the flame of the candle quickly shrank, and a moment later it turned into a wisp of black smoke and went out.

    "Last class, we said that there are many gases in the air, and one of them is the combustion promoter, that is, the oxygen we need to breathe!"

    "The reason why the flame will go out after I buckle the cup is that the oxygen in the cup is limited. The combustion soon consumes oxygen. Without combustion supporting agent, the fire triangle cannot be established, and the flame will go out."

    "We all know that water can put out fire. So why can water put out fire? I tell you, it''s still the fire triangle!" Arthur knocked on the blackboard standing behind him.

    "In the previous section, we talked about the morphological changes of objects. Among them, it is said that water needs to absorb a lot of heat from the surrounding when evaporating, which eliminates the element of ignition source in the fire triangle! Secondly, a large amount of water poured on the flame also isolates the oxygen in the air and eliminates the element of combustion supporting agent in the fire triangle. Therefore, water can extinguish the fire."

    ……

    Two more hours later.

    "Look at the number axis. Two numbers with different symbols are opposite to each other, that is, a and - A are opposite to each other. Note: 0 is neither positive nor negative, and the opposite number of 0 is 0. Without" - 0 and + 0 ", 0 is 0..."

    "At both ends of the number axis, two numbers with the same unit distance, that is, only two numbers with different symbols except zero, are called opposite numbers. Its characteristics are: the two numbers add up to 0, the absolute values of the two numbers are equal, and the two numbers multiply to a positive number and a negative number, that is: - A ^ 2 = - (AA)..."

    "The opposite number of the number a is - A, and the opposite number of - A is a. here a is not necessarily a positive number, so - A is not necessarily a negative number..."

    ……

    Every five days, the Council Hall of Lingfeng castle will become a classroom, and Lord Arthur will turn into a teacher.

    It was not the children in the territory who listened to him, but the bachelor who served as a teacher in the school.

    At the beginning, Arthur had only ten students. These ten were teachers in charge of mathematics and science. As the content of his lecture spread among the bachelor''s degrees, all the teachers of the school asked to come to attend the class.

    Thus, the object of his class has become all the teachers in the school.

    Later, even ilu and Boye, two old bachelors, also joined the student team.

    Up to now, except for the bachelors who can''t get away from work, every five days, most of the bachelors who go to the river gather in the Council Hall of Lingfeng castle to listen to Arthur''s lectures.

    After the class, Arthur sat in his chair tired.

    The morning course not only consumed his accumulated lesson preparation for a week, but also made his legs sour and his throat hoarse.

    It''s not Arthur''s intention to show his ability and find trouble, but he really has no other way. No one is qualified for the job except himself.

    Among the three courses of history, literature and geography, he can''t compare with a bachelor''s degree. But when it comes to mathematics and science, all the river leading bachelor''s degrees together can''t compare with him.

    In addition, many new concepts, new names and new symbols were introduced. Therefore, Arthur had to prepare lessons and fight in person. He first taught the teacher and then the teacher taught the students.

    "Don''t whisper below. Have you written down all your notes? Quickly recall the knowledge points I just said in your mind."

    After pouring a large glass of water, Arthur picked up the test paper: "later, I''ll ask the class representative to send you the test paper. Combined with what I just said, try to do it and take it back for inspection in half an hour."

    With that, Arthur handed the test paper to Leah.

    Yes, Leah is the class representative.

    Since Arthur taught her to read, Leah was like an open mind. She was not only interested in all kinds of Castle books, but also full of curiosity and desire to explore Arthur''s knowledge of mathematics and chemistry.

    After discovering that Leah has this talent, Arthur also intends to cultivate her. He will answer all kinds of questions for her as soon as he is free.

    As Arthur''s maid, Leah naturally has more opportunities and time to get Arthur''s advice than the scholars. Therefore, Leah is a real class representative student in mathematics and chemistry!

    Looking at the scholars in front of him, Arthur said, "if you don''t understand or don''t understand, ask the representative of Lia class, and she will answer for you. If you want to learn knowledge, you should not be ashamed to ask! Now it''s still relatively simple knowledge. If you don''t lay a solid foundation, it will be more difficult to listen to the class later!"

    "Yes, sir!" the scholars replied respectfully.

    In the past, the scholars respected Arthur only out of his noble status, but now, it is more out of their admiration for his knowledge and behavior!

    Arthur had knowledge they didn''t understand at all and imparted it to them selflessly.

    Nodding with satisfaction, Arthur looked at Leah: "Leah, I''ll give it to you here and give good guidance to the bachelors. Many of them are school teachers. If they don''t understand, they don''t have the face to teach students!"

    "Yes, Lord Arthur," Leah agreed with a smile. This is the second time she has answered questions for the bachelors.

    With a smile, "well", Arthur got up and said, "it''s hard for you, but don''t always stand. When they do the test paper, you can sit in my position and watch them answer."

    Leah looked at Arthur with her bright eyes and said, "Sir, I''m not tired at all. Go and have a rest. You''ve been standing all morning."

    Thorne also said, "Sir, let Leah find another chair to sit in."

    "I''ll just stand, sir. I''m really not tired at all. I''ve been sitting all the time during your class."

    Looking at the clever and sensible Leah, Arthur smiled and said, "it''s up to you, but don''t be too formal. Sit down and rest when you''re free. You represent me."

    After Arthur left, Leah began to answer the questions for the bachelors. From time to time, she would draw pictures on the blackboard with chalk in her hand.

    After answering all the questions, Leah gave Arthur the questions, and she copied the written papers one by one.

    When the scholars bowed their heads to do questions, she stood quietly next to the chair symbolizing the power of the Lord.

    There is an unspeakable happiness in Leah''s heart that she can share her worries for Lord Arthu