What issues present the most pressing problems for the u. s.?

aging population
increasing energy costs
lack of natural resources
lack of skilled labor

increasing energy costs

lack of natural resources

Explanation:

sediment layers stop spreading when they reach a barrier or they run out of sedimentary material. lateral spreading is the movement of gently to steeply sloping, saturated soil deposits caused by earthquake-induced liquefaction. i hope this . : )