... life. sand Sand is a loose material composed of fine debris of rock and mineral particles. sandals S andals are open shoes worn in warm weather. sandcastle A sandcastle ... with an opening in the center for a person. keel The keel is the bottom of a ship. landing gear The landing gear of an airplane is the set of wheels used during landing and ... slip and fall. fly When something flies, it goes through the air without falling. Many animals, like flies, butterflies and birds, can fly. People can fly in airplanes and helicopters....