Question Detail

We ought to have saved our environment.

Our environment ought to had been saved.
Our environment ought to have been save.
Our environment ought to have been saved.
Our environment ought to have saved.

Answer: Option C

1. The police caught the culprit.

The culprit were caught be the police.
The culprit was caught be the police.
The culprit caught be the police.
The culprit had caught be the police.

Answer: Option B

2. Open the window.

Let the window be opened.
Let the window will be opened.
Let the window was opened.
Let the window is opened.
Let the window is been opened.

Answer: Option A

3. Priyanka has written these notes.

These notes are written by Priyanka.
These notes has been written by Priyanka.
These notes have been written by Priyanka.
These notes had been written by Priyanka.

Answer: Option C

Explanation:

Note: Please note the use of "has/have"

4. I must help him.

He must helped by me.
I must held him.
He must get help from me.
He must be helped by me.

Answer: Option D

Explanation:

If we have "Subject + Modal Auxiliary verb + first verb + object"
then we change it to

Passive subject + Modal Auxiliary verb + be + third form + by + passive object.

Modal Auxiliary verb are : can, could, shall, will, may, might, should, would, must, ought to etc.