21.
Putting in hard work to help others is what he likes from his heart.

22.
What does agonise me most is not this criticism, but the trivial reason behind it.

24.
He dislikes the word dislike, isn't he?

25.
Who does not know that this was broadcasted ten days ago?

28.
Ravi's father did not want to have spent all his money at the fair.

29.
There is a shortage of well qualified teachers of most subjects, specially of English and Economics.

30.
The prisoners walked slowly for they knew that as soon as they cross the gate the jailer would ask them to jog.