помогите!!!!! очень прошу)) заранее спасибо))

  Отрезки АС и BD пересекаются в точке О, причем АО = 15 см, ВО = 6 см, СО = 5 см, DO = 18 см.

а)           Докажите, что четырехугольник ABCD — трапеция.

б)           Найдите отношение площадей треугольников AOD и ВОС.

кальций -оксид кальция -гидроксид кальция -нитрат кальция осущиствите преврощение и напишите тип реакции

Помогите пожалуйста! Срочно надо!

Найдите здесь ошибки. 

 1. There is large bookshop near the park.
2. It is a large bookshop. My mother sometimes buys English books there.
3. It is a nice sports ground. Everybody Likes It.
4. There is a nice sports ground near our school. Everybody goes there after school.
5. It is for your brother, not for you.
6. It is something interesting in the box. 
7. It is a very interesting story.
8. It is a new picture on the table. 
9. Ann thinks it is a toy, but I am sure it is a bird.
10. It is winter. There is a lot of snow in the forest.

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1. She reads English books.
2. She'd like read the book.
3. I'd like to read the book.
4. She can read English books.
5. She enjoys to read books.
6. We enjoys to read his books.
7. The book is worth to read. 
8. Do they want reading the book? 
9. She wants reading the questions.
10. He decided to read the book.

Сколько понадобится машин грузоподъёмностью 1 целая одна пятаят,чтобы перевезти груз весом 2 целых две третих т?