К 20 г раствора содержащего 5% сульфата железа (2) добавили 20 г раствора содержащего 8% NaOH. Вычислить массу образовавшегося осадка 

В трех стопках 98 тетрадей.В первой на 10 тетрадей меньше, чем во второй и на 8 тетрадей больше, чем в третьей.Сколько тетрадей в первой стопке?

Read sentences a-f and decide if 1-3 are true of false.

a. I drove back home as I'd forgotten my sunglasses.

b. As I was closing the door, I dropped my keys.

c. The phone rang while I was sleeping.

d. I was reading a book when Jack arrived.

e. While Sarah was swimming, Tom went for a walk.

f. Matt went to the cinema when he had finished his homework.

1. As can mean when or because.

2. After when we only use the past simple.

3. After while we usually use the past continuous.