Answer:
1. How did life begin?
2. Are we alone in the universe?
3. What makes us human?
I think the answer is approximately 4.12 billion years since the amount of years is 4.543 billion years
Answer:
A and B
Explanation:
This is because there was emission of gamma (Y) radiations in both the reactions.
The correct answer is D.
Echo refers to the sound that is heard when a sound wave is reflected back from a surface. An echo sound is made when a sound wave traveled through the air, hit a hard surface and get reflected back. Generally, hard surfaces reflect sound wave while soft surfaces absorb sound waves. Reflected sound waves are used in application of some devices that are used in range and direction finding.
Answer:
d.
Explanation:
liters is a measure of volume, it is an SI accepted metric system unit
