By about age 7, those who have not been exposed to either a spoken or a signed language gradually lose their ability to master any language. This illustrates the importance of for language acquisition.

Serious period

Explanation:

Language acquisition is the process that can take place at any period in life. At age less than 7, child will learn his/her first language called first language acquisition most of the time native language at a rapid rate, complete, not require instruction. If a child as not been exposed to any language at age 7, it would seem impossible for that child to learn anything about any language without first first language or knowing something about general language in general.

proper noun

explanation:

a proper noun is the name of a particular place, person, or thing. england and america are a proper noun because it is a particular place.