Acid precipitation can dissolve aluminum from soil. As aluminum is dissolved, it can flow into lakes and contaminate the water. High concentrations of aluminum in lakes is fatal to many forms of aquatic life. This scenario provides evidence for which of these concepts?

nothing certain is known about what happened, but it seems that the country declined gradually, perhaps due to bad government, or, more likely, due to a series of bad harvests, which resulted in widespread and recurrent famine.

the han greatly expands the chinese empire. the han dynasty retains the centralized bureaucracy and unified political system of the qin but adopts and grafts upon this the confucian view that government should be run by educated, ethical men.

explanation:

the constitution gives congress the power to regulate commerce "among" the several states.

immigrants from northern and western europe continued coming as they had for three centuries, but in decreasing numbers