Unionid mussels are native to the Hudson River in New York State. In the early 1990s, zebra mussels were introduced into the Hudson River. The table shows the number of unionid mussels and zebra mussels over the course of six years. How did the population of unionid mussels change after zebra mussels were introduced? Why did this change occur?

answer:

sequence 1- deletion

                  2- duplication

                  3- insertion

                  4- substitute

                  5- inversion

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.