What communication breakthroughs are connected with each of these dates? 25,000 BCE -

6,000 BCE (8,000 years ago) -

1,500 BCE -

600 CE -

1,450 CE -

These  breakthroughs are connected with each of these dates because they are forerunners of an invention that is a milestone in human communication: the printing press.  

About 25,000 years ago  humans learned to speak. Next, The first picture writings date from 8,000 years ago. Followed by the first evidence of an alphabet which comes from Phoenicia around 1,500 BCE. In 600 CE The Chinese introduced woodblock printing. Finally, Johannes Gutenberg invented the first practical printing press in 1,450CE .

not to sure sdi, strategic defense initiative

the answer is c. many americans held nativist or racist views