Ребят, помогите, предложения нужно написать на ин.яз (русском - перевод) в пассивный залог

Ex 2

1 A strange noise can be heard in Texas 2 An explanation for the Hum has not been found (by scientists). 3 Yetis are said to live in the mountains 4 The Naga fireballs were seen by many people last night 5 The lights are believed to be UFOs