Change the following sentences into passive: 1 numerous scholars studied the ancient circle 2 numerous scholars studied the ancient circle 3 It is unknown who built the stone monument 4 A million tourists attend the site every year 5 They built this ancient stone circle in 3000-2000 BC
1) The ancient circle is being studied by a lot of students
2) The stone monument was built by unknown person
3) The site is being attended by a lot of students every day
4) This ancient stone was built by them in 3000-2000 BC