отрезки ac и bd пересекаются в точке o так что ao равен oc известно что ab паралельны dc докажите что ob

Помогите пожалуйста решить уравнение методом выделения полного квадрата: x^4-8x-9=0

почему при электризации трением на телах появляются равные по абсолютному значению, но противоположные по знаку заряды?

The beautiful princessMai Chilived in her father’s palace. She never went outside its high walls. Her father, the King, wanted to choose her a husband. He didn’t want her to meet a handsome young man and fall in love. So she stayed locked in the palace and the people of the city never saw her. But they talked about the poor, lonely princess and they were sad.

One day a famous general, Xiao Lu, came to the city. The King wanted to thank him for winning so many battles. He wanted to give him a medal. Of course, when Xiao Lu came, the King didn’t wantMai Chito meet the soldier, so he shut her in her room. When the King saw that Xiao Lu was younger and more handsome than any other general in the army, the King thought, “I was right to lock up my daughter. I don’t want her to fall in love with this man. I want her to marry a prince. Xiao Lu is just a soldier.”

But Xiao Lu knew from the people of the city that the King had a beautiful daughter. So, that night, he searched the castle until he found her room. Very quietly, he went in and woke her up. It was dark, she was frightened and she started to shout loudly. Xiao Lu stopped her and escaped with her. They went to the mountains and they lived in Xiao Lu’ castle.Mai Chifell in love with him and they got married. The King was angry at first, but in the end he was happy when his daughter and son-in-law came to live in the palace with their children. The old King loved his grandchildren.

1. Match the beginning of the sentence with its ending according to the text:

1)Mai Chistayed locked in the palace

A) he didn’t want his daughter to fall in love with a soldier.

2) Xiao Lu was a famous general

B) until he found her room.

3) The King shutMai Chiin her room as

C) and the people of the city never saw her.

4) At night Xiao Lu searched the castle

D) and went to the mountains.

5) He woke her up and they escaped together

E) who won a lot of battles.

F) because she was ill.

2. Decide if the sentences are true or false. If the sentence is true, write A, if it is false, write B.

1) The people of the city often sawMai Chi.

A) True

2) The King wanted to give Xiao Lu a medal for winning a lot of battles.

B) False

3) The King introduced Xiao Lu to his daughter.

4) Xiao Lu was an ugly old man.

5)Mai Chi, Xiao Lu and their children came to live with the old King.

C2H5CH3-------->C2H5CH2-OH