This would only be done through the use of artificial insemination, and for an entire cow herd, not just one lonely cow. One cow will be bred to one sire, another couple cows will be bred to another sire, etc.
if they didnt they would be extinct by now
No.
Yes, cows mate with bulls to reproduce. Bulls are the male cattle that mate with the female cows to produce offspring. This mating process is essential for the continuation of the cattle population.
No, not usually.
it is called serving
No ... cows can't survive underwater, and the octopus can't graze on land ...
Yes they do because all cows are girls and all bulls are boys
Cows can breed for as long as they are productive, which can range from one to 15 years or more.
It depends on the bull. Some may be able to breed up to 5 cows per day, others maybe only 1 or 2. It all depends on how receptive cows are and whether they're in standing heat at the time. A lot of breeding occurs at night, so you may see the bull breeding only a couple cows during the day.
kangaroo
It's a way of producing offspring and to pass one's genes on to the next generation. Cows don't live forever (nor do any animal on this planet), so it's crucial to mate to have other offspring pass on their genes to the next generation.
Cows will show signs of heat cycle (they will bellow, they will mount or stand for mounting), the bull will smell that she is in heat (often the cow will urinate and the bull will smell the urine-this is referred to as the Phleaman response). They will then breed.