Question

1.The trees was cut down ruthlessly (begin:they)
2.Shea will be selected for the competition only if she goes for the auditions.(begin:unless)
3.No one will deny that children have worked hard.(begin:everyone)

Answer 1

Answer:

1. they cut down the trees ruthlessly.

2.unless she goes for auditions, Shea wont be selected for competitions.

3.Everyone will agree that children have been working hard.

Answer 2

Here are the correct answers:

1. They cut down the trees ruthlessly.

2. Unless Shea goes to the auditions, she will not be selected.

3. Everyone/All will agree that children have worked hard.

Explanation

1. The verb in the sentence was Simple Past in the active form (cut). When we convert the active voice of Simple Past into passive voice, we use passive form equivalent to the active form. The active form in Simple past is 'V2' or Simple Past form of the verb. The object is made the subject and vice versa; 'by' is added. The passive form in Simple Past is was/were +V3.  

2. According to Oxford Dictionary unless is used to talk about a situation that could happen, or something that could be true, in the future. If you know that something has not happened or that something is not true, ‘if…not’ is used.