как переводится математика по английски

Какие суффиксы у слов:читатель,мыслитель,слушатель?

два маляра покрасили 5/7 стены причём один покрасил 2/7 стены. Какую часть стены покрасил другой?

S+H2O=>????? какая реакция выйдет?

выберите правильную форму в каждом предложении:

1) I was tired because i (had worked/had been working)all day.

2)He didn`t have any money because he (had spent/had been spending)it all on a new computer.

3)She (had waited/had been waiting)for three hours outside the cafe, and she wasn`t very happy.

4)They (had eaten/had been eating) too much and they didn`t feel very well.

5)I (had sat down/had been sitting down) all afternoon so i decided to go for a walk.