Those who learn sign language as teens never become as fluent as children exposed to sign language from birth. this reflects that childhood is a(n) for mastering aspects of language.
a. algorithm telegraphic
b. speech stage
c. critical period
d. universal stage

During the paleolithic, hominins grouped together in small societies such as bands, and subsisted by gathering  plants  and fishing, hunting or scavenging wild  animals. the paleolithic is characterized by the use of knapped stone tools, although at the time humans also used  wood  and bone tools.

The haitian revolution was the result of a long struggle on the part of the slaves in the french colony of st. domingue, but was also propelled by the free mulattoes who had long faced the trials of being denoted as semi-citizens. this revolt was not unique, as there were several rebellions of its kind against the institution of plantation slavery in the caribbean, but the haitian revolution the most successful. this had a great deal to do with the influence of the french revolution, as it to inspire events in haiti. the haitian revolution would go on to serve as a model for those affected by slavery throughout the world.