21.
The main point of his speech was well understood.

22.
On hearing the loud noise, he stopped and got down from his bicycle.

24.
Let's buy a new sari with the annual bonus, can we?

25.
He did many mischiefs.

26.
The boy told his teacher to explain the passage.

27.
I met the two girls, whom I believe, are twin-sisters.

28.
They felt humiliated because they realised that they had cheated.

29.
He grabbed the man from the overcoat and pulled him away from Ritu.

30.
His voice was rough and gravelly, as though his throat has had suffered an injury.