The birds that have beaks better equipped for the task of eating worms under ground. Narrow, sharp and strong beaks would be better at digging through the dirt to find worms. So birds with these types of beaks would be fitter and thus, would survive.
D.
Photosynthesis creates energy that the plant stores, and cellular respiration utilizes the energy.
The person will generally have to sit int he boat for about 6 hours, as in 24 hours, there are two low tides and two high tides. However, he can still get out of the boat and walk back to shore, it will just be that his boat will be stuck for the next 6 hours until high tide comes again.