Which two body systems, when working together, give your body shape and allows you to move around?

The answer is; the skeletal system and the nervous system

The skeletal system (muscle and bone) give you rigidity and enable your legs to support your weight. The muscles also act on the bone as a fulcrum allowing it possible for them to contract and make motion possible.

The nervous system   is important in the coordination of movement. The brain is the center for locomotor action. This ensures you are able to place one foot in front of the other in sequence and moving your arm in concert.  

the two answers are a, the population of birds with large beaks will increase on the island, and c, the trait for large beaks will be passed on to future generations through natural selection. the reason for that is because if the birds that have beaks developed for eating small seeds lose all of their food, they will go hungry and eventually starve because they physically cannot eat the large seeds, therefore making the population of large beaked birds higher. also, if the trait of large beaks are dominant on the island over small beaks, then over time the large beaked birds will reproduce more and more, while the smaller beaked birds will reproduce less and less because they can't survive with the food provided. that leads to the trait of small beaks disappearing and the trait of large beaks taking over the island.