Curious Kids[1] is a series for children of all ages. If you have a question you’d like an expert to answer, send it to This email address is being protected from spambots. You need JavaScript enabled to view it.[2].How do they build things like tunnels and bridges underwater? – Helen, age 10, Somerville, Massachusetts When I was a kid, I discovered a Calvin and Hobbes comic strip[3] that
Curious Kids[1] is a series for children of all ages. If you have a question you’d like an expert to answer, send it to...