Learning that occurs not as a result of a purposeful attempt but as a by-product of performing a task is learning.

the united states constitution is the supreme law of the united states. the constitution, originally comprising seven articles, delineates the national frame of government. its first three articles embody the doctrine of the separation of powers, whereby the federal government is divided into three branches: the legislative, consisting of the bicameral congress; the executive, consisting of the president; and the judicial, consisting of the supreme court and other federal courts. articles four, five and six embody concepts of federalism, describing the rights and responsibilities of state governments, the states in relationship to the federal government, and the shared process of constitutional amendment. article seven establishes the procedure subsequently used by the thirteen states to ratify it. it is regarded as the oldest written and codified national constitution in force.

two jet streams that directly affect the formation of weather in the continental part are a polar jet and a subtropical jet. they are responsible for the transportation of weather systems, which directly affect people. the polar front is the boundary between cold air from the north pole and warmer equatorial air. both the polar jet and the subtropical jet blow from the west to the east, and follow the boundary between cold and warm air.

the strongest jet streams are polar jets, while subtropical jets are somewhat weaker.

the right answer is c. the polar jet stream is generaly stronger than the subtropical jet stream.