Folded layers of rock can form a wavelike pattern of troughs and ...

[audragclark]

Folded layers of rock can form a wavelike pattern of troughs and crests. The layers near the trough (i.e. downward fold) form
 
  A) shear.
  B) a thrust fault.
  C) a tension zone.
  D) a syncline.
  E) an anticline.

Question 2

Describe the typical air masses that affect North America. Give their source regions, physical characteristics and properties, and typical directions of movement.
 
  What will be an ideal response?

[cam1229]

Answer to Question 1

D

Answer to Question 2

Continental polar: cP, cold dry and stable. Source regionhigh latitude North America over continents.
Maritime polar: mP, cool, moist, unstable conditions. form over northern oceans and moves generally southward.
Maritime tropical: mT, form over tropical waters in the Gulf/Atlantic and the Pacific. Both warm and humid, but stability differs between source regionsmore unstable in Atlantic. The Pacific ones move generally eastward and the Gulf/Atlantic ones move northward and eastward to impact the continent.
Continental tropical: cT, hot, low relative humidity, stable, occurs in summer over Central America and southern U.S. This moves northeastward but generally not extensively.