"Qianye, what is the time when the past is completed?" Taocheng looked at the English tense written on the English book and looked confused.
Well... I was speechless, then I took the English book in his hand, pulled a piece of paper, and started writing it on it, because I was afraid that he would not understand it after telling him for a long time, and I hated talking the most.
In fact, just figure out the basic structure of this tense, and you don’t need to remember that much. I recalled it and then picked up the pen and wrote: It means that the actions completed at a certain moment or before the action can also be said to be the past.
The action of time about the past, that is, "the past of the past". It can be expressed by preposition phrases such as by, before or an adverbial clause (in a compound sentence, an adverbial clause directed by a time link is called an adverbial clause in time).
It can be represented by an action that represents the past, or it can also be represented by context.
Subject +had + past participle vpp.(done)
1. Affirmative sentence: subject + had + past participle
2. Negative sentence: subject + had + not + past participle
3. General questions: had + subject + past participle?
Affirmative answer: yes, subject + hadd
Negative answer: no, subject + hadn't
4. Special question sentences: Special question words or phrases + general question sentences (had+subject+past participle)?
5. Passive voice: subject +had(hadn't) +been + past participle
"This is the basic structure. If you encounter this type of sentence, you have to use a specific answer to choose the answer." I drew on the paper and spoke lightly.
Oh, Taocheng nodded, then took the piece of paper and went to memorize it silently.
"Shit, Qianye Supervisor, how to solve this binary system of equations?" Haitang was stumped by a calculation problem.
I pulled off a piece of paper again, and then started the question, but it was done in just one minute. Then I handed it to Haitang, "The equation containing two unknown numbers and the terms containing unknown numbers are all 1 is called
binary equations of first order.”
Then write the general steps next to the question you have made:
The general steps of using substitute for elimination are:
[1] Choose an equation with relatively simple coefficients to deform and turn it into the form of y = ax +b or x = ay + b;
【2】Substitute y = ax + b or x = ay + b into another equation, eliminate an unknown number, and thus turn the other equation into a one-in-one equation;
【3】Solve this one-element equation and find the x or y value;
[4] Substitute the calculated x or y value into any equation in the system of equations (y = ax +b or x = ay + b), and find another unknown number;
[5] Connect the values of the two unknown numbers obtained in braces, which is the solution to the binary equation of first order.
The general steps to eliminate elements using addition and subtraction are:
[1] In a binary system of first-order equations, if the coefficients of the same unknown number are the same (or are opposite numbers), they can be directly subtracted (or added) and eliminated an unknown number;
【2】In a binary system of first-order equations, if there is no case in 1, you can choose an appropriate number to multiply the two sides of the equation, so that the coefficients of one unknown number are the same (or are opposite numbers from each other), and then put the two sides of the equation
Subtract (or add) separately, eliminate an unknown number, and obtain a one-number first-order equation;
【3】Solve this one-element equation;
[4] Substitute the solution of the obtained one-element equation into the simpler equation of the coefficients of the original system of equations, and find the value of another unknown number;
[5] Connect the values of the two unknown numbers obtained in braces, which is the solution to the system of binary equations.
"If you bring these steps into the formula and choose what you think is the most suitable." I handed the draft paper to Haitang. Haitang looked at the words and numbers on it and nodded immediately. It seemed that it only needed to put this piece of paper.
You can handle the exam by memorizing the above.
I sat in front of the computer, wondering, why didn't these guys come to ask me a question for a long time? Did they all understand? That was really great, I raised my head, but I was completely speechless.
The two guys fell asleep leaning on their heads together, and their saliva was almost flowing out.
Alas, I sighed, it seems that there is still only one way. I immediately entered the national test paper center, then adjusted the final exam paper, quickly copied the above test questions, and then went from the side.
The printer was printed out.
Seeing so many test papers produced, I nodded and I could pass the test. Of course, I didn't forget to complete two sets of test papers for myself. The subject I was not good at was also the same for me.
The fatal fatal point.
[Note: Japanese education is different from China, they will learn equations only in the second year of junior high school]