Which is the correct passive voice construction?

1.What is the author's primary purpose in writing this passage?

2.The word "Either" in "Either you or he is responsible" is a/an:

3.The word '$much^{\prime}$ in: "He is much better now" is a/an:

4.The word '$poor^{\prime}$ in: "The poor need help" is a/an:

5.Many a student _____ present yesterday.

6.We saw the sun _____ in the west.

7._____ a lion or a tiger, I would be terrified.

8.The passive form of "They are making a bridge" is:

9.The passive form of “It is impossible to do this” is:

10.Indirect Speech of "She said, 'What a beautiful sight it is!' is:

11.Change to indirect speech - He said to me, "May you be happy!"

12.The old man is blind