Verified answer

Ex 4

A A strange object has been filmed in the sky (by a photographer).

B An unusual craft has been discovered in the Himalayas (by explorers).

C Thousands have been fooled by a Belgian UFO hoax.

D A new restaurant will be opened tomorrow by the mayor.

Ex 5

1 by 2 by 3 with 4 by with

Ex 6

1 were spotted 2 was captured 3 was observed 4 is being examined 5 has not been released 6 is believed 7 will be revealed