Answer: What are you asking??
Oxigen ,nitrogen ,carbon,and hydrogen.
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.
It is because leaves are the main users of photosynthesis in a plant. The sunlight seeps into the leaves, and the leaves transform the sunlight's energy into sugar; their food.
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The answer is : B) Inner Ear.