What major difference have scientists discovered between today's whales and the fossils of whales' ancient ancestor

One common educational practice is to chart students' progress over time so that students can see their own improvement. these progress charts often lead to higher student achievement in the absence of other observable forms of reinforcement. the effectiveness of such charts in changing behavior illustrates the role of reinforcement as:

Multicultural studies report that the best way to develop babies' sleep rhythms seems to be

According to your text, systems of government in the united states are shifting from what to what?