The PK-3 class from Hyde-Addison Public School embarked on a field trip two weeks ago just blocks from its school on O Street: the Georgetown Shell at Wisconsin Avenue and Q Street. Teachers Melissa Redlinger and ShaQuanda Humble, along with parents, arranged the visit. Shell manager Bobby Ladson and his team — including Rob Green and Jack Coehlo — were happy to explain automobiles and car tools. Curious three- and four-year-olds asked such questions as “How does the car know to turn on?” and “Why aren’t tires smooth?” The hydraulic car lift was a big hit as were the doughnuts and juice at the end of the lesson.