Imagine, Sing & Learn: The Mighty Merrimack. Mass. Audubon Society Joppa Flats Education Center. Newburyport. 10:00 a.m. to 11:30 a.m. and 2:30 to 4:00 p.m. This parent/child program is designed for the creative, curious, and active preschooler. Each 90-minute session offers a structured series of activities including original songs, movement, dramatic play, story time, and a thematic snack. Parent-child, $10 members, $14 non-members. Additional children, $8 members, $12 non-members. 978-462-9998. www.massaudubon.org/joppaflats