When the eyes are closed, the day passes, and if the eyes are not closed, a lifetime passes.

Shang Yiyun has never understood the meaning of this sentence, but at this moment, he understands it, but the price is that he was reborn in the first semester of the third year of high school, this year, he is faced with an important choice in his life.

Whether to continue to study art and step into the hall of the university through the art examination, in the last life, he passed this road and entered a second college, and after graduation, he began the road of hard interior designer.

Staying up late every day to make pictures, the physical state is getting worse, this is to take your own life to make pictures, every day after washing your hair, there will be a lot of hair in the basin.

It won't take long for the top of the head to be bald, and in a buzzword, that's really "extremely smart".

However, in the face of various requests from customers, he could not refuse, sometimes, Party A's customers called in the middle of the night to ask to modify the drawings, they had to get up from the bed and turn on the computer to modify the drawings.

Before the contract is signed, the designer is God, and after the contract is signed, the customer is God.

Soon, Shang Yiyun noticed that something was wrong, he stood on the podium with the blackboard in front of him, and after observing the surrounding situation, he immediately understood what kind of situation he was facing.

He is a student in Class 10 of the county No. 1 middle school, this class is a math class, and now, he is solving a big problem of solid geometry, and he is very helpless about this situation.

Just traveled to the student days, and faced with such a hellish start, it was simply inhumane.

Back then, he was also a student who punched the college entrance examination for five years and kicked the simulation for three years, but now he can only think about it in his mind.

When he was in high school, he was very good at mathematics, and he could score more than 130 points in mathematics every time he took the exam, but in the four years of college, he never came into contact with mathematics again, and after work, there was little mathematics knowledge left, and it would be good to keep some basic knowledge in his mind.

As for those trigonometric formulas, sequence formulas...

has slipped quietly from his mind, six years, no matter how deep the memory is, it can't resist the passage of time.

At this moment, something in the shape of an electronic screen suddenly appeared in front of his eyes, which frightened him almost to scream, this situation was too weird.

Language: Beginner (95/100)

Math: Advanced (120/1000)

English: Beginner (45/100)

Politics: Beginner (36/100)

History: Beginner (43/100)

Geography: Beginner (33/100)

Physics: Elementary (8/100)

Chemistry: Elementary (5/100)

Biological: Beginner (9/100)

Fine Arts: Bachelor's Level (2300/10000)

The level of knowledge is divided into: elementary, advanced, bachelor's, master's, doctoral, peerless, and eternal.

Seeing this situation, Shang Yiyun was very helpless in his heart, reborn as a student, those skills learned in society have not been forgotten, but the knowledge before college is no longer one in ten, so there is this embarrassing situation.

However, the knowledge of solid geometry, he still remembers a few theorems in his mind, if the problem in front of him is analytic geometry or function, he really has no way, fortunately the problem he is facing now is solid geometry, this question, in the college entrance examination six questions, the difficulty is not high, it belongs to the middle to low.

After reading the whole question, he already had a general idea in his mind.

As shown in the figure, it is known that the side of the regular triangular pyramid P-ABC is a right-angled triangle, PA=6, the orthographic projection of vertex P in the plane ABC is point D, and the orthographic projection of D in the plane PAB is the point E, which connects PE and extends AB to the point G.

(i.) prove that G is the midpoint of AB;

(II.) In the figure, make the orthographic projection F of point E in the plane PAC (explain the method and reason), and find the volume of the tetrahedral PDEF.

In this type of question, the first question is basically a proof question, which is not very difficult, even if you have forgotten a lot of previous mathematical knowledge, this kind of question can still be solved.

As for the second question, it is a bit difficult, and it is necessary to master some knowledge about trigonometric functions, and this knowledge, he has forgotten, standing on the podium for a few minutes, he can only helplessly say two words, no.

The other students in the classroom were stunned when they heard this, every time they took the exam, Shang Yiyun's math score was in the class, at least the top three, and now they said that they couldn't do this kind of three-dimensional geometry question, they liared the ghost.

No matter what others thought, Shang Yiyun stepped off the podium.

"Shang Yiyun, what's wrong with you today, it's not like your usual performance at all. ”

He had just returned to his seat when a girl in front of him had a look of surprise on her face.

The female classmate in front is called Chen Feiyun, and the other party is the same as him, and will choose the path of art, but the other party did not go to Hangzhou for training, and this class of students studying in school was almost wiped out, and I heard that they repeated their studies for a year and were admitted to Shangyang University.

He found that his two table mates also looked at it, and in the face of this situation, he was very helpless, he couldn't say that he was reborn, and that the mathematical knowledge had almost been forgotten, and if he really said that, he would really be a fool.

"I was a little unwell today and not in good shape. ”

After saying this, he stared at the math test paper in front of him, holding his face in a daze with one hand, his mind was like a mess, what happened to him was too outrageous, he was afraid that this was a dream of Nanke, and after waking up from the dream, he would return to the kind of life that kept staying up late to change the map.

In the past six years, he left too many regrets, the biggest regret is that he did not study art early, only took half a year to go to Hangzhou for intensive training, only luckily admitted to a second college, after graduation in the face of those peers, there is no competitiveness at all, and finally worked in a small and medium-sized company, talking about the plan, measuring the room, drawing, two years, experienced all kinds of cruelty in society, so that he is very nostalgic for the beauty of campus life.

I never thought that one day I could return to the third year of high school, the art exam seven months later, and the college entrance examination a year later, these are two very important exams that can almost be said to determine his future.

Many companies stipulate that the minimum standard for recruiting employees is undergraduate graduates, but in fact, those large companies will not look at the resumes of those undergraduate graduates, and there are many resumes of those 985 and 211 college graduates, not to mention an ordinary two-book graduate, which has become the rule of the workplace.

Many people say that academic qualifications are nothing, and ability is the most important thing, but without the stepping stone of academic qualifications, how can you show your ability.

The bell rang for the end of class, and it also woke up Shang Yiyun who was in a daze, he had been in a daze for nearly twenty minutes, and in the face of such a thing as rebirth, no one could treat it calmly.

In the next geography class, I vaguely remember the appearance of the geography teacher, but before the fourth period, there is still something to do, he is the representative of the math class in the class, and he needs to go to the teacher's office to get his homework, tomorrow is Saturday, and he can go home after three self-study classes.