The days turn shorter and colder. Leaves fall from the trees. Let's find out why! Caen hojas gives young learners a basic introduction to leaves and why they are important for trees. --This Spanish text series, Yo sé (I Know), introduces early readers to beginning science topics. Each book includes a list of words to look for in the text with callouts that match the word to the image on the page where it appears. Questions at the end of each book encourage readers to connect further with the text.