Question

7. . child : childhood :: infant :
8. vain : vein :: sore:
9. violent : non violent : : modest : ...
10. manace : threat :: momentum : ....​

Answer 1

Answer:

7) infancy

8) soar

9) boastful/conceited

10) impetus

Answer 2

Answer:

Child : childhood :: infant : infancy

Vain : vein :: sore: soar

Violent : non-violent : : modest : boastful

Menace : threat :: momentum : Power / energy

Explanation:

From the question, the state or the period of child can be referred as his childhood. Similarly, the state or period for an infant can be referred as infancy. From ‘vain : vein’, the meaning of both words are  entirely different, yet the pronunciation is same. Similarly, the word sore : soar i.e. both the words’ meaning are different with same pronunciation.  

The opposite of violent is non-violent. Thus the opposite of modest is boastful. The synonym of menace is threat and hence the synonym of momentum is power.