"<span>Introduction of American plants such as maize to Europe" is the only option that was a part of the Columbian exchange, since this exchange revolved primarily around the exchange of goods from the New World to Europe. </span><span />
Answer: There is pollution in the east river
Explanation: If we think about it cant be a lack of food as it talks about having a large food source. Nor can it be climate change as that would result in a low yellow Perch population. it cant be they aren't able to catch the bird. So the only logical answer is a pollution that the birds are adapted to.
The cold war started because the United States feared the Soviet Union was trying to control the world. There wasn't an actual war but there was lots of tension and fear of nuclear war.
I'm pretty sure the answer is it goes to the Senate