Some reasons:
→ They're cheap and common animals.
→ They can be either a source of meat, skin (leather) or milk.
→ Farmers benefit a lot with them, since what they produce are things of everyday consumption.
→ You don't need to spend much to be able to have them (mostly only with land).
Hope it helped,
BioTeacher101
True, though the Hadean period is one exception.
It was not until the year of 1952!
The answer is C. It states that energy can only be moved from object to object.
