Answer:
I think its c Scientists cannot determine how it changes.
d). It increases over time.
Carbon is found in the non-living part of the hydrosphere, atmosphere, and Geo-sphere, as carbonate (CaCO3) rocks and dead organic matter, such as humus in soil.
So, the Sun's light takes about 8.3 minutes to reach us. This means that we always see the Sun as it was about 8.3 minutes ago. ... The nearest large galaxy to us, Andromeda, is 2.5 million light-years away. So, we see Andromeda as it was 2.5 million years in the past.
Answer:
When a cold front overtakes a warm front, it creates what's called an occluded front that forces warm air above a frontal boundary of cooler air masses.
Explanation:
The presence of a cold front means that cold air is advancing and pushing underneath warmer air. This is because the cold air is ‘heavier,’ or denser, than the warm air. Cold air is thus replacing warm air at the surface.
The excretory system allows animals to remove metabolic waste their bodies. Many of these substances are potentially toxic. in Mammals nitrogenous toxins like urea are expelled through liquid urine while in reptiles and birds the nitrogenous compounds are expelled as a solid. This allows birds and reptiles to use less water in the processes of metabolism.