Problem: Given the question: What is the missing first step of the following process: - The pollution negatively affects the water quality - The pollution negatively affects the health of plants and animals - The plants and animals have shorter, less healthy lives - The plants and animals do not reproduce very well - The number of plants and animals decreases over time - The quality of water gets worse and worse as there are no plants or animals to clean it - Eventually there is nothing living in the water and it is unusable -
++++++++++++++++++++++++++++++++
The answer is:
Pollution enters natural water sources such as rivers and lakes

Problem: Given the question: What is the missing first step of the following process: - Nephrons in the kidney filter the blood - The waste that is filtered out mixes with water - Become urine - Ureters carry urine out of the kidneys.
++++++++++++++++++++++++++++++++
The answer is:
Blood carried into kidney by the renal artery

Problem: Given the question: What is the missing first step of the following process: - This mass creates high core temperatures - The mass decreases - The red giant can no longer fuse the carbon and oxygen in its center - The gravity of the star can no longer hold the outside layers - The layers break away - Only the inner core remains - This inner core is known as a white dwarf.
++++++++++++++++++++++++++++++++
The answer is:
A red giant burns mass