The article claims that invasion of zebra mussel cannot stopped and is threatening to the population of freshwater fish and provides three reasons of support. However, the professor explains that there are many ways which people can use for controlling its spread and refutes each of the author's reasons. First, the reading claims that history of the zebra mussel's spread suggest that the invasion might be unstoppable and human transportation was the cause of it. The professor refutes this point by saying that people killed all of the ocean animals.He states that people should empty the ballistic water on their ship, which was full of the zebra mussels, and refill with ocean water to kill the animal. Second, the article posits that when
