The Precambrian time refers to the time 4.5 billion to 542 millions year ago. This period is characterized by having reduced atmosphere and included reduced compounds. Scientists believed that atmosphere at that time was devoid of free oxygen and CO2 was present in excess. Before the complex life evolved on the Earth, the Precambrian Earth's ocean contained dissolved carbon dioxide.
Answer:
Aquatic life quickly suffers the effects of watershed pollution, while new pollutants introduced into ecosystems alter wildlife habitats. This reduces biodiversity by eliminating some species and introducing new, invasive ones that destroy the native species.
Explanation:
The correct answer is "anisocoria". Anisocoria is the condition when the patient's pupils are normally unequal and the patient is asymptomatic and clinically stable. This should be differentiated in cases of patient with a relative afferent pupillary defect such is patients with optic neuritis or retinal detachment or in patients with neurological deficits.
I think it’s a&c. I could be wrong, but at least try