1. The bright and intelligent youth of the country can glorify her.

Answer: The bright and intelligent youth of the country can lead her to glorification.
Or
The bright and intelligent youth of the country can bring glorification to her.

2. This plan needs to be modified.

Answer: This plan needs modification.

3. The company agreed to provide one-time food.

Answer: The company made an agreement to provide one-time food

4. Venu went to cancel the tickets.

Answer: Venu went for the cancellation of tickets. (Preposition ‘to’ changed to ‘for’ in order to suit ‘noun’)

5. The gardener examined the plants carefully.

Answer: The gardener made a careful examination of the plants, (the ‘adverb’ also changed to ‘adjective’ in order to define noun)

6. Sanyukta has prepared everything nicely.

Answer: Sanyukta has done a nice preparation of everything.  (you also need to supply a suitable article for noun).

7. Vitamins and minerals nourish our body.

Answer: Vitamins and minerals provide nourishment to our body.

8. They want to settle this issue.

Answer: They want a settlement of this issue.

9. The king announced to celebrate the victory.

Answer: The king announced the celebration of the victory.

10. Your words contradict your gestures.

Answer: There is a contradiction between your words and your gestures

11. Nobody can tolerate such a brutal act.

Answer: Nobody can tolerate such an act of brutality.

12. The two lines are exactly congruent to each other.

Answer: There is an exact congruence between the two lines.

13. Shilpa behaved in a humble manner.

Answer: There was a humility in Shilpa’s behaviour.

14. Sagar is confident enough to win the gold.

Answer: Sagar has enough confidence to win the gold.

15. They led a happy life.

Answer: They led their life with happiness.

16. The nurse devoted a warm care to the patients.

Answer: The nurse devoted a care with warmth to the patients.

17. How wide is the path?

Answer: What is the width of the path?

18. Granny was always generous to her grandchildren.

Answer: Granny always showed generosity for her grandchildren.

19. Alok’s words are not clear.

Answer: There’s no clarity in Alok’s words.

20. They are menaced by being poor.

Answer: They are menaced by poverty.