Scientific knowledge is durable, but it is also open to change. An example is the way in which organisms are classified. At one time, the kingdom was the highest level of classification. Today, the highest level of classification is the domain. One domain used in classification is Eukarya. What reason would scientist have for adding another level of classification

the answers are a and c

since there are no options posted i'll give you a few examples.

a dolphin's flipper, bird's wing, cat's leg.

imagine a line passing through the center of earth that goes through both the north pole and the south pole. this imaginary line is called an axis. earth spins around its axis, just as a top spins around its spindle. this spinning movement is called earth's rotation. at the same time that the earth spins on its axis, it also orbits, or revolves around the sun. this movement is called revolution.