Вставьте слова по смыслу!4)... you ... part in the competition recently.a)are

Воткните слова по смыслу!
4)... you ... part in the competition recently.
a)are taken b)have taken c)were taken
5)Computers .... by the students at their lessons.
a)are used b)is used c)were used
6)A nice picnic ... arranged last moth/
a)is b)was c)are