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The day a signal came from space – level 2
15-08-1977On August 15, 1977, American astronomer Jerry Ehman looked at the...
The day a signal came from space – level 3
15-08-1977On August 15, 1977, American astronomer Jerry Ehman carried out an...
The day Russia sold Alaska to the United States – level 3
30-03-1867Russians arrived in Alaska in 1741. They established the first permanent...
