Answer:
A scientist’s presentation of experimental results at a scientific conference
Explanation:
Respiratory and circulatory systems work hand in hand to expel wastes. respiratory system removes CO2 and the circulatory uses the blood as a medium to move excess salts and water from source to sink.
Answer:Warming of the Earth's climate and associated changes to oceans were the most likely causes of the extinctions. At the end of the Permian Period volcanic activity on a massive scale in what is now Siberia led to a huge outpouring of lava.
Explanation: