This ingenious spin-off of Beaty and Roberts's Rosie Revere, Engineer aims to get children asking questions, finding treasure where others see trash, and dreaming up solutions for such real-world "problems" as figuring out how to open a door with one's elbow. "Let's build a simple catapult," reads one entry; parents needn't worry--the catapult consists of a plastic spoon affixed to an empty thread spool, and it's designed to launch marshmallows. Lined and graph-paper backdrops underscore the engineering theme, and Roberts's energetic pictures of Rosie and her classmates entertain while walking readers through hands-on activities that include creating a solar oven (aluminum foil plays a key role) and a paper towel tube vehicle. Games, profiles of inventors, and an all-around focus on pie-in-the-sky thinking add up to an activity book with substantial depth. Ages 5-7. Author's agent: Rebecca Sherman, Writers House. (Apr.)Copyright 2017 Publishers Weekly, LLC Used with permission.