An oar is to a canoe as a steering wheel is to a car. This is a functional relationship. The oar helps steer the canoe in the way that the steering wheel steers the car.
A penny is to a dollar as a small house is to a skyscraper. This relationship shows smaller to larger. A penny is much smaller than a dollar; a house is much smaller than a skyscraper.
A toddler is to an adult as a caterpillar is to a butterfly. This relationship shows the young and the adult. The caterpillar is an early stage of the adult butterfly.
A palm tree is to a pine tree as a bathing suit is to a park This relationship shows an opposite warm to col Palm trees grow in warm climates and pine trees grow in cold climates. Bathing suits are worn in warm weather; parkas are worn in cold weather.
Hat and mittens are to desert as snorkel and flippers are to snow. This relationship shows an opposition. The hat and mittens are NOT worn in the desert; the snorkel and flippers are NOT worn in the snow.