Before 1954, so-called portable radio receivers used vacuum tubes to receive and amplify signals.
History Explorer Results (1)
Related Books (0)
Grade Range:
9-12
Resource Type(s):
Reference Materials
Date Posted:
11/8/2009
This website reviews the early history of submarines and their radical transformation after World War II. Students will learn how submarines were built, how they work, and what they do. They will also learn the story of submariners and their families, Americans who were on the fron
