Расставь знаки арифметических действий и,если нужно,скобки так,чтобы получились верные равенства.

 7 7 7 7=6  

Write questions to the underlined words.

1. They I had been preparing for their wedding for three months.

2. Helen had been painting the floor in the kitchen for two hours yesterday.

3. You had been playing computer games for three hours yesterday. 

4. Mark had been fixing his bike for two hours yesterday.

5. We had been gathering the apples in the garden all day.

568%  и 7,25%  перевести в десятичную дробь

Определите,какие оксиды соответствуют данным кислотам и основаниям.

H2SO4 -

HNO2 -

H2SiO3 -

Be(OH)2 -

KOH -

Al(OH)3 -