Nguồn gốc văn học là gì?

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:

In what region did the industrial revolution began

Cattle are herbivores by nature and feeding herbivores a diet for carnivores may have triggered a protein reaction known as a prion causing mad cow disease