Answer:
B. to understand the world around us
Explanation:
The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles Argon, or 39.948 grams.
This is the era of recent life that began about 66 million years ago and continues today. It includes the first appearance and Homo sapiens about 400,000 years ago. <span />
