This Instructional Activity is a part of the Lesson 12, Unit 6, Grade 8. An image of a growth experiment may help English language learners understand the context of the example. The words compost and bed may be unfamiliar to students in this context. Compost is a mixture of decayed plants and other organic matter used by gardeners to enrich soil. Bed has multiple meanings. In this context, bed refers to a section of ground planted with flowers.