Answer:
1. D
2. C
3. A.
4. B
Explanation:
1. D. Groups of people make tools of stone: this period is known as the stone age, and it occurred around 1.76 million years ago
2. C. Homo Sapiens make their first appearance in history: from research, the earliest homo sapiens to have been found dated to have existed 200,000 years ago in Africa.
3. A. In the Ice Age, people migrate to parts of North America: the migration was believed to have occurred between the Siberia in Asia (eastern part) and Alaska in North America around 20,000 to 25,000 years ago.
4. B. The start of the Neolithic Revolution: this period was believed to follow the Ice Age, and it began around 12,000 years ago.
The Roman Empire is the empire it began in
<span>I'm pretty sure that it's wrong topic. Anyway, I think I know correct answer. Here it is with missing word: Researchers have found that infant fear is linked to guilt, empathy, and low aggression at 6 to 7 years of age.</span>