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.
To describe a scientist as skeptical, they question existing ideas and a new hypothesis. skepticism is a valuable quality because it shows that scientists is good and open minded.
i hope this helps...
Answer:
positive feedback
Explanation:Because when you get motion that means its positive but if doesn't feel motion than that is negative.
<span>are we talking human reproduction? in this case only 1 egg is implanted. in unusual cases there could be 2 eggs implanted meaning fraternal twins. if 1 egg splits, we get identical twins. with only one egg implanted, there is only 1 kid being produced.
the female has eggs stored from birth. 1 ovary 'pops' once a month to either be discarded via a period or implanted after fertilization. multiple eggs released is usually the effect of fertility drugs making many eggs get released at once. this is unusual unless fertility drugs are in use</span>
Answer:
The partial pressure of oxygen is high in the alveoli and low in the blood of the pulmonary capillaries
