с помощью какой качественной реакции можно открыть анион CO3(2-)?

 

 

Помогите плиз к завтрому надо.

отрезки AD и BC пересекаются в точке о которая является серединой отрезка AD углы BAO и СDO равны.Докажите что треугольники AOD и DOC равны

Do you know idioms? Choose the necessary words to complete or explain them

     1)Jane knows the subject...

A)from cover to cover  B)inside out  С)like

      2)To catch somebody...

A)red - handed  B)blue - eyed  C)short - handed

       3)It happened ' out of the blue' means ...

A)it was unexpected

B)it was painful

C)it happened from time to time

       4)She has a rosy view of things , she..

A)is  B)likes pink colour  C)has many rosy things

        5)He' s playing first fiddle means he's..

A) a good musician  B)a conductor  C)a leader

         6)If you do something at the last moment it means you do it

A)at the tenth hour  B)at the twelfth hour C) at the eleventh hour

         7)To keep fingers crossed means...

A)to wish good luck  B)to envy  C)to be angry

         8)To eat like a bird means...

A)to eat a lot  B)to eat a little  C)to eat grain

        9)To work round the clock means to work...

A)all day  B)near the clock  C)from time to time

       10)The rival hit him in the eye , so now he has a...

A)purple eye B)blue eye  C)black eye

решите уравнение tg пх/4=1.