Bones of snakes are very loosely fused together like in humans. Hence these bones can move individually allowing the snakes to be really flexible. The ribs of snakes do not join like those of humans but instead, have free ends and do not have a sternum.
It is called hydrosphere
It is the total water in Earth.
Explanation:
In Earth’s history before the Industrial Revolution, Earth’s climate changed due to natural causes not related to human activity. Most often, global climate has changed because of variations in sunlight. Tiny wobbles in Earth’s orbit altered when and where sunlight falls on Earth’s surface. Variations in the Sun itself have alternately increased and decreased the amount of solar energy reaching Earth. Volcanic eruptions have generated particles that reflect sunlight, brightening the planet and cooling the climate. Volcanic activity has also, in the deep past, increased greenhouse gases over millions of years, contributing to episodes of global warming
The study of statistics. Like the increase or decrease of things. For example birth rates or the size of the human population.
I hope this helps :)