I don t know how to do the questions.,Find the answer on the Internet, right?。。。

Of course it's not right, I don't know how to use my brain. Always rely on others, and no one will help you during the exam. When doing homework, don't go online, complete it independently, even if you copy the Internet, you should also understand the ideas and methods of doing the questions, and you won't be worried about the same problem next time.

I've had this experience too, and it's a common occurrence for many people. Rest assured, this is quite normal.

The main thing in class is to understand the concepts and basic methods, and it is easy for us to understand when the teacher explains them, but in fact, because the mind thinks independently, we don't really understand it, and this concept has not been integrated and cannot be applied well. Inferences are based on the premise of mastery of knowledge and rich experience in doing questions. It's like if you just keep in mind that 1+1=2 is the truth, but you don't understand it, you don't know the process and method of inference, and your thinking is vague, and you encounter 2-1=?

Naturally, it is stupid.

Therefore, it is very important to preview before class, you must first form the basic framework of knowledge, and then listen to the teacher to make it easier to touch the class, and some things that you don't understand during the preview will suddenly become clear, so that there is a "epiphany" process, and the impression will be more profound. But after this, it does not mean that all the blind spots have been swept away, and there must be shortcomings. Don't be in a hurry when you encounter a topic that you can't do when you first learn a content, start with the basic questions, and learn more about the concepts when you come upside down.

After laying a solid foundation, it will be much easier to do the following.

Textbooks are the basis of everything, don't underestimate basic concepts: they are important!

Internet dependence, which lacks the ability to think on your own!!

Affect the accumulation of children's knowledge structure. Learning is a step-by-step process, the answer to the question that you don't know, you haven't digested and absorbed, and the knowledge points have not been mastered, and the next time you encounter this question, it will still be a roadblock.

Searching for answers on the Internet for a long time will lead to a dependence on computers. When you leave the computer, you will be helpless when you encounter a problem.

Anything is not absolutely harmful and unhelpful, if you really can't think of it, or there is no one to ask for advice, look up the answer on the Internet, and then think about it and understand and find out why, it will also get twice the result with half the effort. Provide us with a shortcut to solve the problem.

First of all, correct it, 35 3 105 70m s 35s = the length of the bullet train laughing bridge length The parentheses are talking about the length of the bridge 21 35 3 So the answer is correct, which means that the sedan can be regarded as a point, and the distance taken by Yan Xun including the bridge car 35 3 = 105s is the bridge length, and then the distance traveled by the sedan is replaced by the bridge length of the Changxiao bullet train, and the answer can be finally obtained.

The displacement is 150*1 3=50mm

12*2/3=8v

Therefore, the voltage book contains the range of the old rock for [, state socks.

1) Because A, D, and E are all tangent points, the line from the center of the circle to the tangent point is perpendicular to the tangent line, that is, AB is perpendicular to AD, Ad is perpendicular to CD, and OE is perpendicular to Tongfeng to BC. It is easy to obtain triangle AOB and triangle OBE congruence, triangle OCE and triangle ODC congruence. So bc=x+y.

The perpendicular line from b to cd intersects cd with f, df=x, fc=y-x. From the Pythagorean theorem, 12 2+(y-x) 2=(x+y) 2, simplified to x*y=36

2) cd=6, then ab=6, abcd is rectangular.

3) ab=4, then the local index cd=9, the shaded part = trapezoidal area - semicircle area = 78-18pie