Указать инфинитив

[Лида]

указать инфинитив;1.We were taking part in the construction of an industrial project
2 Will you be making any experiment tomorrow afternoon
3 They have just constructed the new building for the theatre
4 To solve this problem the researchers have been working hard for years

[size=85][color=gray]Добавлено спустя 1 минуту 4 секунды:[/color][/size]
английского

[English Guru]

1) to take part
2) to make
3) to construct
4) to solve; to work