Answer:
The air is really a mixture of many different gases, and each gas has its own properties. The composition of air is not constant. It can vary from time to time and place to place.
Answer:
You could thank them for all their hard work and talk about one thing this year that you enjoyed doing with them or something i guess
Explanation:
Twins share the same genes, but siblings born at different time does not share the same genes.
It's empty or fairly large, making the sounds from your hands bounce of the walls and therefore having it echo
Sex chromosome: X and Y
Autosomal chromosome: the remaining 22 chromosome
Answer is B
