Continuing dissolution and collapse may lead the the coalescing ...

[Davideckstein7]

Continuing dissolution and collapse may lead the the coalescing of sinkholes to form a
 
  A) rise. B) doline.
  C) karst valley. D) disappearing stream.

Question 2

What accounts for the coastal straightening and the formation of a longshore current?
 
  What will be an ideal response?

[paavo]

Answer to Question 1

C

Answer to Question 2

In general, wave actions straighten coastlines. As waves approach an irregular coast, the submarine topography refracts the approaching waves around the headlands (protruding rocks of resistent material). This energy becomes focused around the headlands and dissipates in coves, bays, and submerged coastal valleys. The result of this wave refraction is a redistribution of wave energy. Different sections of the coastline vary in erosion potential, but the long-term effect is coastline straightening.

Waves usually approach the coast at a slight angle. As the shoreline end of the wave enters shallow water, it slows down, while the portion of the wave in the deeper water continues to move at a faster speed. The velocity difference refracts the wave, producing a current that flows parallel to the coast in the prevalent direction of the incoming waves. This is called a longshore current or a littoral current. It also transports large amounts of sand, gravel, sediment, and debris along the shore.

[Davideckstein7]

Wow, this really help

[patma1981]

Gracias!