Answer:
a Jackson rivaI
it is because the use of word make it sound as if they are a rival
Answer:
The Urinary bladder, the ureter, and the urethra are all organs that belong in the execratory system.
The heart and spinal chord are not organs in the execratory system. The spinal chord belongs to the nervous system and the heart belongs to the circulatory.
Because evolution itself is a very slow process. Having said that, the chance of having a continuum of various animals would mean that evolution would have progressed very fast. Because evolution is slow, different species establish themselves for different ecological niches and environments, this enables them to become better through time at a certain environment which then leads to eventual diversification in the number of species.