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

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

Water flows along the east coast and across the western tropical pacific towards south america, while they both are directed towards that way,  el niño does not directly affect the southern flow of water along the coast. 

Answerdistinguish between the mercalli scale and the richter scale;

Answer sinking and cooled;

The answer is d) rift